Why does MAIL keep forgetting my password?

It depends what you mean by "regularly".

It's possible that this has nothing to do with your computer and is your ISP checking that you are who you say you are.

ISPs frequently perform maintenance to their databases and as a security feature (to protect you) may periodically ask you to reconfirm your password.

It happens to me on a regular basis -maybe once a month? No big deal. It's normal that it should happen.

Matthew...

Open Mail, go to the menu bar click Mail > Preferences then select the Accouts tab then the Account Information tab.

Make sure the password in keychain is the same as you have under Incoming Mail Server.

It could be that the current keychain is corrupted. Go to Keychain Access, select Passwords on the left.

Right or control click your mail keychain then click Delete.

Now re enter the password in the Account Information (Mail > Preferences) window. It should ask you to save that data to a new keychain.

And, you can run Keychain First Aid from the Keychain Access menu bar. That may help also.

I don't think Tom's suggestion that it is actually the ISP requiring validation is at all likely. Unless your ISP is also your mail service provider, they have no possible connection to your email, let alone being able to validate your password. Perhaps what was meant was that the email service provider is requiring revalidation? Again, this seems unlikely via an app using a standard API - I'm not familiar with the details of POP/IMAP, but it's hard to see how it could require manual reentry of the *same* password, even if they wanted to. (It's easy to see how they could require you to *change* your password, of course.) Anyway, it's certainly not what is happening to me, as my desktop is the only one of three devices, all accessing the same email provider, that it happens to.

It is also quite annoying if you use gmail Google's excellent two-step verification process the way it's intended, as you have to generate and reenter a new application specific password every time the mac forgets it.

I think there is something else going on with the keychain.

Using the "Keychain First Aid" link is probably the thing to try first. It's quick and has done the job for me three times now.

Select Keychain Access in your Apps menu.

Then select Keychain First Aid under the Keychain Access menu.

I've been having a similar problem for a while now. I have 4 accounts in Apple Mail. It often asks me for passwords for my 2 hotmail accounts and my icloud account. It never happens for my main Gmail account. I have the same accounts synced to my ipad and iphone, and have no problems on those devices ever, so it is not a server side error as far as I can tell. The repair Keychain suggestion previously posted find no errors, so I'm not sure what the problem is. It doesn't happen every time, maybe once every couple of days on a different one of the three accounts each time. It is still annoying though.

After one month of trying to rectify this problem,

I found this website:

www.att.com/esupport/article.jsp?sid=KB412563

Prior to being directed to this, ATT tried to tell me it was a macintosh problem. Apparently it is not!!

Sometimes, if I delete keychain, it works, sometimes not. Sometimes if I change password, mail works, sometimes not. It was driving me absolutely crazy. The problem only began when I went from OS10.5 to 10.6. Apparently ATT can't keep pace.

Glad you have found a solution to your issue, but this isn't the problem most of the rest of us are having.

Thanks. I think this did help for me - at least my mac hasn't forgotten my google pasword for a while, but has recently started forgetting the password to another email account regularly.

This problem is getting worse for me. Keychain has not lost the password for the mail account which was the original problem for a few weeks, but is now losing the password for another account several times per session - sometimes within a minute or so. Keychain repair finds no issue, and I have entered the correct password many times in both the keychain popup and account settings.

It's a little unfortunate that @Minchy marked @Tom's answer which is pretty obviously wrong as having solved the problem - I don't know if Apple regularly look at these forums, but if they do presumably they don't look at problems marked as solved. I'm reluctant to start a new thread, but perhaps it's necessary.

I know this will annoy the fanboys (and as someone who owns a pro, mini, tv, ipad and iphone you can't accuse me of being anti-Apple), but this is exactly the sort of issue that drove me away from Windows: after a while things just start breaking or slowing down for reasons no-one really understands, there is no official acknowledgement or support, and there ends up being no solution other than the unholy "reboot -> reinstall -> reblast OS" progression.

This helped cure my Mail from doing the same:

http://805creative.com/blog/what-to-do-when-apple-mail-keeps-forgetting-your-pas swords.html

I, too, have different accounts from different providers and when the issue came up, it came up for all of them.

Simple fix, I hope it helps a lot of folks out there with a pesky problem.

Cheers,

Nick