Can not send e-mails from account but can receive

Question

I have my e-mail account with ATT Yahoo.
I received an account verification notice yesterday from ATT and I responded and they said I was verified.
However after I did that I could not send e-mails from my Imac desktop but I am receiving them.
I spend 4 and a half hours, yes 41/2 hours with both Apple Care and ATT and they could not correct the problem. Both discussions were with upper tier support personnel.
Here are some facts that make this an odd issue:
(1)
I have other e-mail boxes from ATT and they can send and receive e-mails.
(2)
MY laptop can still send and receive e-mails from the e-mail account that is only receiving with my Imac.
(3)
All the settings are exactly the same and both Apple Care and ATT checked them.
Is there anybody out there that may have an answer ?
Both Apple Care and ATT blamed each other.
My concern is that today I received another e-mail trying to verify my e-mail address for another e-mail address from ATT.
I called ATT and they did not know why, I DID NOT open it up and trashed it.
ATT has put a filter on my other e-mail accounts and hopefully that will end any problems with them.
The account that has the issue is my main account and I cannot trust leaving it and am trying to avoid having to change it.
Greg

Answer 1

Hi Rachel, For what it will be worth, I was like a dog with a bone about this, so I decided to give it another go. I have success on both boxes. Here is what I did, I warn you now it was a lengthy process. Before you begin download all the upgrade steps from X.5.0 to X.5.6 as single stages ( for me the combo's did not work) and have them ready to use.
1st Backup all your mail to CD/DVD not on the box. Check for any unsent mails anywhere in the box and then throw out all of the mail bits that are anywhere on the system in any folder. 2nd Install & Archive, 3rd Start up from Install DVD and check/set permissions, reboot. Enter all your ISP details to mail, see if you can send a mail to yourself. If not dump all the mail you tried and the .plists, reboot and install next update in the series, enter all details as before, try and send etc. If this fails dump again and reboot install next update etc.
I started at X.5.1 and got to vX.5.4 before I got a result in that sys asked me if this server will do, I said yes and I got mail out. The server name was different that was offered but when all was over it showed as the correct one that it should be on port 995. I must add that I had the spinning cog wheel for quite some minutes before anything happened. I continued on this way for the rest of the updates. 1x1 until v.6 was reached. That was only on the G4, I now had to do it all again on the MacPro. This one was not so co-operative in that I had to do it twice, but now it also has Mail running. It is funny though that I had to reach X.5.4 on both machines before it came right. On the G4 I was using a retail disc and on the Intel the supplied for discs.
Others on here may have a better and quicker way, but for me this did work. I am sure that there is a problem in either the mail app itself or the production of the Master DVD's.
Whatever, good luck.