Blocked outgoing email in Exchange

We are running SBS 2003 with Exchange Server 2003. The purpose of this question is more of an understanding how email works with exchange server. The problem started about two weeks ago when we switched ISP to Comcast. At that moment email was being blocked
by Hotmail and Gmail. We would get the following message back.
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<nhnr.org #5.5.0 smtp;550 OU-002 (COL004-MC4F51) Unfortunately, messages from 73.189.0.xxx weren't sent. Please contact your Internet service provider since part of their network is on our block list. You can also refer your provider to <a href="http://mail.live.com/mail/troubleshooting.aspx#errors.>"
target="_blank">http://mail.live.com/mail/troubleshooting.aspx#errors.>
MXTOOLBOX says that the public ip address comes on one blacklist - Spamhaus ZEN.
Here is the question. If I send mail through exchange to a hotmail account it will be bounced back and undeliverable with the above message. If I configure a POP account and send an email to hotmail it will successfully go through. Why does the POP work and
not the Exchange?
Thanks
Chris

Thanks for the reply.
Are you configuring the Exchange server as your SMTP server for your POP3 client?
That is correct.
I'll also ask the following, to see if we can fix your Exchange delivery issue:
Do you have an SPF record in DNS?
Yes we do have an SPF record setup in DNS zone file.
Have you configured your system to send through the COMCAST SMTP systems, or are you sending direct using DNS? If so, is the IP address of this system included in the SPF record you have in DNS?
The mail is setup to be sent through DNS. Are you talking about the public IP address or the IP address of the server? Either way neither of those IP address are in the SPF record.
If not, is your own IP address included in your SPF record in DNS?
The mail is hosted by Bluehost and their IP address is in the SPF record.
Have you contacts SpamHaus to determine why your IP address is on their blocklist?
No I have not contacted SpamHaus yet. I initially thought that is was Comcast problem but then they said it was not. Anyway after trying different things I setup an email account (not using exchange) and was able to send email to the
previously blocked addresses. So I thought it might be some config problem.

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Inpect and block outgoing emails.

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As others have mentioned probably what you want can be done via Transport Rules.
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>> It is important for me to inspect and block internal emails too(not only emails going out of organization). I need to support Exchange 2010, 2013.
Then using a routing agent
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Block outgoing email because of VPN server

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Airport blocking outgoing emails?

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Did you change any of the ports on the AirPort Extreme, particularly port 25? Can you open up a terminal window and telnet to port 25 on your smtp server? If you don't know how to telnet to port 25 on your server, then let's suppose your smtp server's name is smtp.some.com, so you would type
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Verzon Blocking Outgoing Email Server

Have read on other posts regarding something like this. Its not the port as I have chanced between 25 and 587. There is no set up issue and no I do not need to reinstall Windows.
I have three ISPs due to frequent travel. In the US I am able to send and reveive email from my Verizon account using Outlook without problems. Can even do this using a Verizon compeitor's servie to access the Internet.
When abroad, incoming email using Verizon is OK. Outgoing is blocked. This is consistent.
Can Verizon comment on this? Either admit it and I will find an alternative or provide a solution. A "whitelist" inquiry was made but unanswered. I read on another post where Verizon danced around a FIOS cussomers exact same complain.
You have 2 business days or I'm filing an FCC complaint and encouraging everyone with the same problem to do so. It's not so much the blocking but hte failure to provide a workaround for legitimate use, failure to answer, and inclination to be indifferent while taking money form customers.

If I understand your complaint correctly, you are unable to use Verizon's outgoing server (outgoing.verizon.net) on networks outside of the US.
What error are you getting?
If a forum member gives an answer you like, give them the Kudos they deserve. If a member gives you the answer to your question, mark the answer as Accepted Solution so others can see the solution to the problem.
"All knowledge is worth having."

Does Verizon block outgoing email?

I have three email accounts, one from gmail and two from owned domains. I use Thunderbird to recieve and send email. For the past week, I have not been able to send email from one of my email accounts. This is the error that I receive:
An error occurred while sending mail. The mail server responded: Unauthorized relay msg rejected. Please check the message recipients and try again.
I have checked my settings, and nothing has changed in the last week. The only "work around" I have is to use send through one of my other email addresses.
Email comes in fine for all three email addresses. And I can send fine with two of them, gmail and one of my owned domains.
Please let me know if Verizon has started to block the sending of some emails and what I might be able to do about it.
Thank you,
Anne Plouffe

Verizon recently started implementing port 25 blocking as a way to combat spammers on their network. If you are using your non-verizon.net address to send via a pop3 client, this may be the cause of your issue.
There is more information available at http://www.verizon.net/port25
If you have any questions about the information found there just say so, and myself or one of the other forum members will do our best to find an answer for you.
Hope this helps!
If a forum member gives an answer you like, give them the Kudos they deserve. If a member gives you the answer to your question, mark the answer as Accepted Solution so others can see the solution to the problem.
"All knowledge is worth having."

Blocking OUTGOING eMail to certain addresses

In looking up this question, I found this http://discussions.apple.com/thread.jspa?messageID=3321398&#3321398 and was wondering if I could change the RegEx to:
/^To: .*<annoying@domain\.com>/ DISCARD
so as to deny the server from sending any email to the annoying eMail address?
And instead of quietly, make it known to the sender that the address is not allowed, denied, can't be sent to, should not be disturbed, etc...

Almost.... except that the "To:" header is not present when the message first goes from the mail client to your server (or at least that is what I have found).
The only header which can be searched is the first one added by your server (this is the bottom one if you look at the Full Headers of an incoming email), e.g,...
Received: from [10.0.0.105] (unknown [10.0.0.105]) by mail.panoramicscotland.com (Postfix) with ESMTP id 4D3AB45133 for <[email protected]>
So your entry in the header_check file would be (for the above)...
/^Received.for.<[email protected]>/ REJECT No sending to this address!
The ".*" each side of the "for" will expand to the other text in the header.
What the sender will get is an immediate "Error" message displayed by their email client, displaying the text after the REJECT text as the reason for the error.
Give it a go - it's real easy to set up.
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Outgoing Emails fails after Port 25 blocked by email administrator

Hi, our email team administrator has blocked the port 25 and restricted user to use SSL port 465 instead. The share point SMTP email setup page only shows TLS encryption check box (no ssl encryption check box available)
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Thank you.

Hi Layman,
According to your description, my understanding is that you want to configure the SMTP to use port 465 for outgoing email in SharePoint.
Per my knowledge, Exchange server will secure communication over any port, but will not use SSL, so there is only TLS encryption in SMTP.
To use port 465, we can add the port 465 under Network tab to the Receiver Connector for SharePoint Outgoing email. And then TCP port number on Outbound Connections in
DSMTP Virtual Server properties.
More references:
http://blogs.technet.com/b/tirumals/archive/2012/03/17/step-by-step-configuration-of-outgoing-emails-from-sharepoint-to-microsoft-online.aspx
http://support.microsoft.com/kb/829721/en-us
http://social.technet.microsoft.com/Forums/exchange/en-US/8dc08cf8-8662-4a02-a181-f821e8d59d06/exchange-smtp-using-port-465?forum=exchangesvrgenerallegacy
For more information, you can post your question to the forum for Exchange: http://social.technet.microsoft.com/Forums/exchange/en-US/home?category=exchangeserverlegacy .
More experts will assist you, then you will get more information relation to Exchange.
Best regards.
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Victoria Xia
TechNet Community Support

Exchange server cannot send outgoing email

We are experiencing some issue with the outgoing email , we found out that some email cannot reach our client email.
if the customer is using exchange server, it seems there is no issue.
However, if customers use other server.. like lotus or notes,,etc, there are issues.

Can you send to a Gmail or Hotmail account?
Otherwise, SMTP traffic to outside clients should not depend on any sort of password replication.
Even if the partner was using something like mutual TLS (unlikely), that has to do with certificates, not passwords.
One thing you could do is enable protocol logging on the Send Connector to see what happens when your Exchange server attempts to talk to the client's messaging system.
Bharat Suneja (MVP) wrote an excellent article on how to enable this and where to find the resulting logs:
http://exchangepedia.com/2007/05/exchange-server-2007-logging-smtp-protocol-activity.html
Directions for 2010 and 2013 are included.
Now, reading the log can be a challenge but if you need to get to the bottom of this, you may have to make this effort.
EDIT: Of course, if you need help with that, feel free to follow up.
Please mark as helpful if you find my contribution useful or as an answer if it does answer your question. That will encourage me - and others - to take time out to help you.

Outgoing emails being blocked by spamhaus. Blocking my IP address

Good day
My outgoing emails are being blocked. Spamhaus has blocked my IP address. How do I unblock it? This is the error message that I receive.
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
[email protected]
SMTP error from remote mail server after MAIL FROM:<[email protected]> SIZE=484112:
host mta6.am0.yahoodns.net [98.136.216.26]: 553 5.7.1 [BL21] Connections will not be accepted from 41.76.215.245, because the ip is in Spamhaus's list; see http://postmaster.yahoo.com/550-bl23.html
Please help as this is a business address
Thanks

Your email provider controls the IP address they assign you. Only they can clear the reputation of a blacklisted IP address. Contact them.

Outgoing emails contain firewall WAN IP in headers instead of dedicated Exchange IPs

Hi All,
I have 2 CAS/HT Servers configured viz Microsoft Load Balancer and 2 Mailbox Servers. I have configured 1:1 NAT on my Firewall pointing to NLB Virtual IP.
WAN IP: xx.xxx.xx.80
Exchange IP: xx.xxx.xx.81
There is no problem with incoming packets which works perfectly but, my outgoing email packets are going through firewall IP (xx.xxx.xx.80) and not exchange IPs (xx.xxx.xx.81). I can see this firewall IP in the email headers.
What is it that I need to correct on my cisco to make sure all packets are going through my Exchange IPs?. One method I think is to create an outside dynamic NAT rule with source IPs of my 2 CAS/HT Servers & NLB IP which will point destination to my
Exchange public IP but then I start thinking what is the point of having NLB configured? Also, will not the packets get distributed
by firewall to select any host from the pool of 3 source IPs (2 CAS/HT & NLB)? Is there a method to fix incoming packets to one host only?
Appreciate your time for answering.

Well, although this would seem to be the best place to ask the question, you are asking for us to give you a way to configure your firewall properly so that Exchange is NAT'd outbound. This question would be more appropriate for a firewall vendor
specific forum as your question is related to their devices.
That being said, I can provide some basic information. Have you confirmed what IP the outside world sees your Exchange server is with tools like whatismyip.com ipmonkey.com? If so, then you need to configure your outbound NAT for Exchange.
What rules do you have currently setup for NAT? I think what you need is something like this:
https://supportforums.cisco.com/thread/2049405
Let us know if that works. Those commands are for Cisco firewalls, so if you have a different firewall, let me know.
JAUCG - Please remeber to mark replies as helpful if they were or as answered if I provided a solution.

Outgoing email blocking other emails, won't delete

I have an email in my outbox, that won't send, open or delete and it is blocking all the other outgoing emails I have! Once I click on it to do anything the activity viewer just spins and spins, doesn't time out, and I have to force quit Mail. There is no attachment, the email is blank (or won't load when I click on it), and the size says 1.1MB. What can I do?
iBook G4 Mac OS X (10.3.9)
iBook G4 Mac OS X (10.3.9)

Try deleting it from the hard drive directly -- it should be in:
~/Library/Mail/Mailboxes/Outbox.mbox/Messages
If not, you may have to get more creative. Backup your Mailbox folder and possibly Mail preferences before doing anything creative, though.

Outgoing email blocked.

For historical reasons my email servers are hosted by a US ISP and I use BT merely for access to the internet. However outgoing email is being blocked - the error message reports that my BT-assigned WAN IP address is blacklisted and can be found on the Realtime Black List server, b.barracudacentral.org.
BT _ why would your IP addresses be blacklisted?
Thank you
Solved!
Go to Solution.

This is a BT customer forum, so messages do not go to BT, however there are a large number of community members here, so there is a good chance you will get help.
If you are on a normal dynamic IP address, then restarting your router normally gives yo a new IP address.
There are some useful help pages here, for BT Broadband customers only, on my personal website.
BT Broadband customers - help with broadband, WiFi, networking, e-mail and phones.

Dreamhost blocking SMTP outgoing email sent via MiFi 4510L hotspot

I've been using a MiFi 4510L as my only internet connection for about a year, and have been happy with it to date. Dreamhost.com is my email host (and web domain host).
I haven't been using the MiFi for a few days. Today I was unable to send any messages via the MiFi through Dreamhost's SMTP (outgoing email) server. This happens both when sending from my laptop's email client (Apple Mail) and also from my iPhone when WiFi (i.e. the Verizon MiFi connection) is enabled. It's not a mailserver authentication issue -- incoming email works, Dreamhost webmail send and receive works, and I can send from the (AT&T) iPhone with WiFi turned off (i.e. through AT&T's cellular network). I contacted Dreamhost support, who said:
- - - - - (begin Dreamhost response) - - - - -
DreamHost now performs spamhaus RBL look ups when using an smtp client such as Apple mail. This is to prevent spam from leaving our network. The issues you are describing is what happens when you attempt to send email from an internet service provider (ISP) that is on the spamhaus blocking list. Switching from wifi to 3g will change that IP address that we look up prior to sending the email. For the device that is blocked we can only recommend that you contact the ISP and ask them to either give you a different IP address or work to get their IP's delisted.
- - - - - (end Dreamhost response) - - - - -
I take this to mean that Verizon 4G LTE IP addresses have somehow been added to Spamhaus's database. Has anyone experienced this issue with sending email through a Verizon device using Dreamhost SMTP? What are my options?
Message was edited by: John Ciccarelli (New information: Dreamhost suggested using WhatIsMyIP.com to determine my IP address. It returned 166.250.33.162 and sure enough Spamhaus has that in its PBL and XBL lists. However, I'm using Authenticated SMTP (port 587), not the unauthenticated port 25. Are Verizon servers somehow listed on Spamhaus?)
Message was edited by: John Ciccarelli
More research: I repeatedly shut down and powered up the MiFi. Each time up, WhatIsMyIP.com returns a slightly different IP: 166.250.33.162, 166.250.32.186, 166.250.34.151, etc. Lookup shows these IPs are associated with vzwdomain.com or myvzw.com, not surprisingly. So presumably the MiFi gets mapped to a different actual IP each time it connects. The first of these 3 IPs showed up in Spamhaus's PBL and XBL lists; the other two just in the PBL list. Perhaps if I keep powering off/on it'll eventually connect via an IP that isn't on Spamhaus's list.

Are you using Mail app? You need to make sure the Outgoing Mail Server settings are exactly how your ISP recommends. So give them a call.

How to filter/check outgoing email BEFORE it is sent?

I want to write a set of rules to check outgoing email *before* it gets sent. For example: I have 2 contacts with very similar names and autocomplete occasionally means that I send an email to the wrong person. I want to be able to avoid potentially troublesome situations by specifying that an email with certain keywords never gets sent to specific addresses. I'd like a warning to pop up, or just to have the email shunted into a special local mailbox, if it meets certain conditions prior to being sent out. I am using Apple Mail and Outlook 2011 with an Exchange server. Is there any mail client, or script or extension that will allow me to check emails for specific things before they are sent out?

Hi Raju,
Try this. Create another dataprovider within your web template? This new dataprovider refers to a similar query, but this query definition should restrict values CG1, CG2, CG3 and CG4. Assign this dataprovider to your checkbox. Then make sure the properties of the checkbox affect all other dataproviders.
Also, if this list is static, you could create an HTML checkbox object coding the options (cg1, cg2, cg3, and cg4) programmatically. Then add javascript code to produce the proper filtering based on the users' selections.
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Larry

Blocked outgoing email in Exchange

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