Mail.app can't connect - but Thunderbird can.

Question

Mail.app can't connect - but Thunderbird can.

So, I've got a group of laptops that were all working fine with Mail.app until today, when I changed ISPs.

Must be an ISP problem, right?

Well, no - because from the exact same machines I can configure Thunderbird to the same IMAP accounts and everything works fine.

In addition, I fired up an old PowerMac G5 and added the problem email accounts to that machine's Mail.app - and they work fine!

This is driving me crazy, because which accounts are broken varies from machine to machine, along with the symptoms. On one machine, I can get an IMAP connection if I turn off SSL - but in Thunderbird, and on the other machine, SSL works fine. On two machines, the outgoing SMTP won't connect - but for different accounts - and on Thunderbird both SMTP connections work fine.

Any suggestions on what to look for? I've pulling my hair out, here.

Macbook, Mac OS X (10.6.4)

Posted on Aug 4, 2010 1:44 PM

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Answer 1

Aug 4, 2010 1:51 PM in response to Michael Heinz

First thing is the run Connection Doctor on each of these Macs, in Mail.

Ernie

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Answer 2

Aug 4, 2010 1:56 PM in response to Ernie Stamper

And that was the first thing I did.

It showed no useful output except to eventually say it couldn't connect.

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Answer 3

Aug 4, 2010 2:02 PM in response to Michael Heinz

Mail will require you to use the form of Username the server requires, and it does not typically guess whether it should be Username or Username@domain.xxx as the entry for the Username box. I assume you have checked that? But Mail 4.x does do some assumptions with some popular provider accounts.

Did Connection Doctor report anything about whether SSL is supported in those instances you cited?

Ernie

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Answer 4

Aug 4, 2010 2:20 PM in response to Ernie Stamper

Remember - these accounts are working over SSL with Thunderbird and in Mail.app on an old machine that I just set up mail on after these problems began. That said, the exact message for the SMTP connections is:

Could not connect to this SMTP server. Check your network connection and that you entered the correct information in the Account preferences. Also verify that the server supports SSL. If it does not, deselect the "Use SSL" checkbox in the Advanced tab of Account

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Answer 5

Aug 4, 2010 2:21 PM in response to Ernie Stamper

For SMTP, it should be using port 465 - but Apple mail seemingly doesn't let you specify if you want 465 or 587.

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Answer 6

Aug 4, 2010 2:23 PM in response to Ernie Stamper

Pfft. On a whim, I reconfigured one of the bad accounts from IMAP to POP. Same destination host, same account info, but it works. Doesn't solve the outgoing problem, though.

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Answer 7

Aug 4, 2010 3:03 PM in response to Michael Heinz

In Mail Preferences/Accounts/Account Information, click on the arrows beside the name of the SMTP, choose Edit Server List, then under the Advanced Tab in the resulting dialogue select Use Custom Port and directly enter 465 (or 587 as may be required). The default list can be problematic if anything causes a temporary interruption, causing Mail to try the other port options.

Ernie

Message was edited by: Ernie Stamper

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Answer 8

Aug 4, 2010 4:19 PM in response to Ernie Stamper

Ernie - that worked on one machine. I'll try the others now.

Thanks.

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