Ah! I went through these from a menu instruction and did make a change and couldn’t get back. Both Gmail accounts had different setting (one had none and the other had IMAP and the one from my older server email had pop 3). I ended up changing settings. At the time the first email I set up showed neither server while the other had IMAP . I found two passwords but they didnt work and I used a couple of Google 8 code back up. So my two last passwords (not coded) did not work.
Ok if I understand you correctly, you have 2 Google Gmail accounts, and one was setup as POP and the other was setup as IMAP and you are now getting invalid name and password within eM Client trying to access either account.
So first off, go to Gmail via the web and see if you can get into them online in your browser webmail.
Now “if you can’t get into both Gmail accounts online via webmail”, then you need to go to the Google account forgot password link and reset it, or contact Google support via either their community forum or support link.
Now “if you can get into both your Gmail accounts via webmail”, then you need to go in eM Client to “Menu / Accounts” and click “Add account” at the top and enter your email address and “follow the automatic account wizard” which will setup the account/s as IMAP and near the end of the wizard you will get prompted to click allow to give eM Client access to your Gmail account.
Note: Both Gmail accounts “due to Google changes announced a few years ago”, now need to be setup the same as IMAP using the automatic account wizard which uses the OAuth passwordless token setup as per the eM Client Google workspace support page link.
So if your existing Gmail POP account within eM Client has old email in it, “then after resetting up your accounts again as IMAP”, drag your old Gmail POP account messages and any custom POP account message folders to whichever new IMAP account you want them to go to. Then once you are certain they are all moved over, then remove the old POP account. You can see when that’s completed in “Show Operations” via clicking the dropdown on the right of Refresh top left.
Also remove your existing Gmail IMAP account “that wasn’t working”, once you have resetup both accounts again as IMAP using the acct wizard.
Lastly if you don’t get through the automatic account wizard let us know “exactly where you get up to” and what the error message says in the wizard.
Also what version of eM Client you are using and if you have Windows or Mac and OS version.