What ports to forward to server for mail to function correctly?

Question

I recently upgraded to Mountain Lion form lion and am experiencing a MAIL issue (FAILURE)
I beleive I need to restablish or open ports on my router but the common ones don't seem to be doing the trick for users using Outlook. I have the Apple document that talks about the most common used ports but my Netgear router limits me to 20 so I need to narrow down the selction a bit.
Any assistance would be appreciated.
Right now, these are the ports being forwarded: (and yes, many can be eliminated)
Service Name
External Start Port
External End Port
Internal Start Port
Internal End Port
Internal IP address
1
HTTP
80
80
80
80
192.168.15.101
2
VPN-PPTP
1723
1723
1723
1723
192.168.15.101
3
NetMeeting/H.323
1720
1720
1720
1720
192.168.15.101
4
VNC
5900
5900
5900
5900
192.168.15.101
5
mail
110
110
110
110
192.168.15.101
6
mail2
25
25
25
25
192.168.15.101
7
mail3
143
143
143
143
192.168.15.101
8
mail4
993
993
993
993
192.168.15.101
9
Kerberos
88
88
88
88
192.168.15.101
10
Password
106
106
106
106
192.168.15.101
11
SMB
139
139
139
139
192.168.15.101
12
SSL
443
443
443
443
192.168.15.101
13
Mail
587
587
587
587
192.168.15.101
14
email rules
8089
8089
8089
8089
192.168.15.101
15
FTP
20
21
20
21
192.168.15.101
16
SSH
22
22
22
22
192.168.15.101
17
DNS
53
53
53
53
192.168.15.101
18
RPC
111
111
111
111
192.168.15.101
19
SFTP
115
115
115
115
192.168.15.101
20
NTP
123
123
123
123
192.168.15.101

Answer 1

Regarding Outlook. Can it receive, send or neither?
If the problem is sending, two things to look at.
- You are configured for port 587 which is TLS.
In outlook, select TLS (not SSL)
I prefer to enable port 465 which is SSL, this plays well with outlook.
To do so, you need to edit
     /Library/Server/Mail/Config/postfix/master.cf
Look for these lines
#465      inet  n       -       n       -       -       smtpd
#  -o smtpd_tls_wrappermode=yes
#  -o smtpd_sasl_auth_enable=yes
#  -o smtpd_client_restrictions=permit_sasl_authenticated,reject
#  -o milter_macro_daemon_name=ORIGINATING
Uncomment them all. DO NOT remove the space before the -o (its required)
Then issue
sudo postfix reload
Make sure 465 is open in your router
Retry Outlook
587 = TLS
465 = SSL
- Look at your smtp logs, do you see helo errors when you try to send from Outlook?
If so, do this (good idea to do this for ANY installation)
edit
     /Library/Server/Mail/Config/postfix/main.cf
Find    
smtpd_helo_restrictions = reject_non_fqdn_helo_hostname reject_invalid_helo_hostname
Change to:    
smtpd_helo_restrictions = permit_sasl_authenticated permit_mynetworkseject_non_fqdn_helo_hostname reject_invalid_helo_hostname
Then issue    
sudo postfix reload
If this doesn't solve the issue.
Please post whether this is a receiving or sending problem.
If receiving, post output of mailaccess.log(imap) log when you attempt to pickup mail
If sending, post output of your mail.log(smtp) when you try to send.
Jeff