One email account stops working in Lion, despite same functioning settings on iPad and iPhone

Update: in my case turning of SSL for the problem-ridden account solved it - even though I'd obviously prefer to still be able to use SSL, at least I'm receiving mail now.

Yes, I had to do this for both the incoming and outgoing servers for Optimum.

I have a similar problem. For me it is the Exchange account, which happens to be the 1st account listed in Mail > Preferences > Accounts. For me the account works early in the Mail session, but after a while it stops receiving mail. I can still send mail from that account. And when I go to quit Mail it won't shut down normally. I have to Force Quit it. When I relaunch it again I get all the messages I didn't receive for the last several hours. But the process repeats.

The problem began 2 hours after I installed Lion. It has happened to me every day since. I hadn't had the problem at all on Snow Leopard.

I can only establish an IMAP connection with SSL disabled. With SSL enabled I am repeatedly asked for my password and authentication fails each time I give the password (which is correct). Here's what I see:

CONNECTED Jul 30 14:10:20.078 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1b932270

READ Jul 30 14:10:20.688 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1b932270

* OK [CAPABILITY IMAP4REV1 I18NLEVEL=1 LITERAL+ SASL-IR LOGIN-REFERRALS AUTH=PLAIN AUTH=LOGIN] xxx.cs.dummy.ca IMAP4rev1 2007b.404 at Sat, 30 Jul 2011 14:10:20 -0500 (CDT)

WROTE Jul 30 14:10:20.692 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1ace6950

1.7 AUTHENTICATE PLAIN ************************

READ Jul 30 14:10:20.754 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1ace6950

1.7 BAD Missing or invalid argument to AUTHENTICATE

WROTE Jul 30 14:11:04.267 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1acfb9a0

2.7 AUTHENTICATE PLAIN ************************

READ Jul 30 14:11:04.329 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1acfb9a0

2.7 BAD Missing or invalid argument to AUTHENTICATE

WROTE Jul 30 14:11:30.643 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1b95c750

3.7 AUTHENTICATE PLAIN ************************

READ Jul 30 14:11:30.705 [kCFStreamSocketSecurityLevelNegotiatedSSL] -- host:mail.cs.dummy.ca -- port:993 -- socket:0x7faa1acd7990 -- thread:0x7faa1b95c750

3.7 BAD Missing or invalid argument to AUTHENTICATE

Why does it say AUTHENTICATE PLAIN when I have SSL enabled?

The mail server is running IMAP-UW 2007b which has a bug that causes authentication with Lion Mail to fail. Get in contact with your mail provider to update the mail server to 2007f, where the issue has been fixed.

http://www.washington.edu/imap/documentation/RELNOTES.html

Thanks. The system administrator upgraded the software and the problem has been resolved.

Congratulations. But it's impossible that every administrator an ISP around the world upgrade the software only por Mac Mail users. Apple have to release an update NOW!

I'm lucky that I work at a University and Mac users are very important here.

Hello guys,

After a while I figured out what was going wrong with the POP email accounts and Mail 5.

It happens that the new app is using a protocol that was not used by the mail programs as well as by ISP providers.

Now, Mail 5, is questioning the mail servers about capability (CAPA instruction) and most of the servers answer as IMAP by default, even tho they are POP servers.

So when Mail 5 receives this answer, it does not establish the connection and so POP accounts don't work.

My ISP came out with a non conventional solution while they work on the server configuration.

The solution is deleting the POP accounts and recreating them, indicating they are IMAP accounts, but configuring them manually as POP.

To be clear, when recreating the account, the programs asks for the type of account. There you put IMAP.

Further, when it cames to configure the account, you do it manually, configuring the POP and SMTP servers as if they were POP accounts.

What this does is deceive Mail 5 which is specting an IMAP answer, but after that the account works as POP.

It worked for me and my ISP (Fibertel).

Hope this works for you too.

Hi Alfacruxis:

Your solution is THE SOLUTION! Problem solved here! It worked for me and my ISP too. I'm sending an receiving mails ok. My ISP is Fibertel too. Thank you very much!