I have been using KMail for years, possibly decades. Starting near the beginning of June, 2022 I began having intermittent problems sending and receiving mail through my Gmail account. Now I have reached the stage where I can neither send nor receive. I have been using POP all this time, and my server settings and password have not changed. The same for the SMTP side. On attempted receiving/download, the error message generated by Kmail(apparently) is
Unable to login to server pop.gmail.com.
Login via SASL(PLAIN) failed. The server may not support PLAIN, or the password may be wrong.
The server said “[AUTH] Username and password not accepted”
About all I can say for sure is that the password and username are correct, they work when I use webmail. The other part about PLAIN I have no idea. Ports and encryption are as required by Google support, and have not changed in years.
Is this a “less secure app” problem? If so, I can’t be the only person encountering this problem, yet I can find no mention of it in the forums. Is there an obvious KMail settings fix?
Thanks for the information about the new authentication methods, and while I see XOAUTH2 as an option for the SMTP side, I do not see this as an option on the receive side under POP. Does this mean I must switch to the IMAP protocol? I have never seen the advantage of this so far, its additional capabilities have never been important.
Always provide enough context for others to understand what you are talking about. We are not looking over your shoulder. You see/do not see where? Kmail? Gmail? Somewhere else?
Anyway - indeed, KMail seems to support OAuth2 only for IMAP. Application specific passwords seem to work (Re: how to use Kmail with the new Google monster? — Trinity Desktop Environment). As mentioned this require 2FA, so your options are - stay with POP, enable 2FA and generate password for KMail or switch to IMAP. Of course there is always an option to open bug report, but I do not hold my breath here.
On Google side POP3 works with OAuth2. E.g. Thunderbird auto-detects it automatically.
Don’t pay any attention to anything from google. Delete your gmail account. The only purpose of google gmail is to get access to the info in your emails for the benifit of google to sell to the highest bidder. They claim security to protect your email from other users while they mine and harvest and resell what they want.
I use linux to get out of google’s clutches amongst other things.
I tested the account assistant with IMAP. Basically I entered my credentials (address and password). I was prompted by google for some additional input. KMail readily opened the gmail inbox.
OK, there has been some progress. I disabled POP in Gmail, and enabled IMAP. Then I deleted my old POP receiving account in KMail, and used the assistant to create a new IMAP account with a different name. Of the two new accounts (receiving/sending) that were created, so far only the receiving one successfully accesses my Gmail account and downloads the mails, although to a new folder structure separate from the one I have been using for about 10 years. The Sending account is not successful, and I get the message:
Failed to transport message. The remote host closed the connection
when I try to send a test email. Authentication is set to XOAUTH2 in the Advanced section of the SMTP/Sending tab.
I failed to modify my existing account (send/receive = localhost) to work entirely with gmail. However I succeeded with a pristine user. SMTP settings used are: SSL/TLS, port 465, XOAUTH2.
