Q: incorrect autofill email in safari

Have a look at Safari, Preferences, Autofill. You can see the list of existing autofill data.  Maybe delete the erroneous one and start again.

Long shot:  Try deleting cookies associated with that website (Safari, Preferences, Privacy).

I think I understand what you are referring to now. All of mine come from the Safari, Preferences, Autofill, OR Safari, Preferences, Password dialogs.  I don't know where else they would be.

One last thing to consider: See "Keychain Access" in your Utilities folder.

I have the exact same problem.  I mis-spelled my email address by 1 letter and now the erroneous entry keeps being auto filled by safari.  I have checked everywhere (Autofill preferences for safari, Keychain) but cannot find where the error is stored and so cannot delete it.  This is so frustrating and has resulted in my not receiving emails as they have been sent to the wrong address.

Please let me know if you have any suggestions.

Thanks.

Please add me to this same list of problems. Safari Autofill has been cleaned (my erroneous email wasn't there) Passwords checked and cleared, Keychain checked and not there. Checked my contacts too without success. In desperation I even checked Word Dictionary. Am wondering where this email address must be stored. Am on on El Capitan 10.11.1
I assume that as there has been no update to this thread for some time before my reply, no one knows.......

See the last post.

Autofill is not working correctly, it adds an extra piece to my email address and I'm beyond frustrated

I added one more post after the one Eric is referring to.

I finally cracked this. I went on line with the Apple Support people. They very patiently went through all of the things I had done, then they were stuck. They suggested a couple of things which didn't work. Final solution was to get to a random log in web site, then before putting in any data like your email that his usually overwritten incorrectly, right (two finger) click on the blank "username/email address" field. This brings up a a selection box of which on option is Spelling and Grammar. Highlight this with your cursor and another selection opens up. Click on the "Show Spelling and Grammar" option and another box opens. This next set is a bit hazy (it was late, I was tired and also desperate for a solution) so bear with me....I had two goes at this and am not sure which one worked so try one then the other...

In the blank top line of the Spelling and Grammar box I put my Wrong ID and then clicked "change". Nothing seemed to happen so I put in the Correct ID and clicked "change". Again nothing seemed to happen.

However when I clicked out of all these boxes, and went to log in to a web page as a test, for some reason this seemed to have cleared the incorrect log in auto-fill. The Apple Support person, who had access to my screen by this time, was amazed and couldn't explain why what I had done had worked.
This was over a week ago and the erroneous log in/auto fill has gone for good.

Hope this helps someone. Apologies that I was't as methodical in getting the certain solution but as I say, try one, then if that doesn't work try the other. One of those should clear it.

I did ask the Apple person to make sure this fix is posted widely on all forums but I don't think they did.

Thanks for this.  I tried your solution and have managed to get rid of the erroneous autofill .  This has been bugging me for ages, as well as causing big problems when the wrong email address is autofilled by safari, so really appreciate it.

Thank you so much for going through the process to figure it out - I've had the same problem and it's been driving me nuts. Your directions aren't hazy - I did the same and although it won't let me "unlearn" the bad spelling, somehow it now likes the correct spelling again.