Symfony/mailer v6.4.3 + gmail SMTP issues

Maybe add to the docs https://www.drupal.org/docs/contributed-modules/drupal-symfony-mailer → ?

I found that if you copy the password to the clipboard, it contains spaces between each block of four characters. Removing the spaces worked for me.

I have the same error on v1.4.1 as well. I will also try downgrading to v1.4.0 to try to resolve it.
Has anyone been able to isolate the issue? Perhaps a patch?

Thank you @griz ! You save my day)

I have created this account just to thanks @griz. You saved my day. My problem was not Drupal but Mautic's symfony mailer DSN.
I did everything in my power. Wasted the whole day and then finally with enough google search I found your comment and removed the spaces between the app password for Gmail and then it worked like a charm.
I previously used App Password with space in different applications and they worked, so never thought of this. However thank you again and again.
And for SEO: Mautic Gmail Google Mailer SMTP error can be fixed if you use App Password and remove spaces between those App Password.
You are welcome!

Thank you @griz

Indeed, when copying and pasting, the blank spaces are included. Removing them solved the problem.

I guess many people will have the same problem :(

We started having this issue recently. I've reset the password for the gmail account and at /admin/config/system/mailer/transport with still the same error as #1. Using symfony/mailer v6.4.18 and drupal core 10.3.13

Unable to downgrade to symfony/mailer v6.4.0 because of core version. Was able to go down to 6.4.7 but it didn't fix the issue.

Where are you seeing spaces in the password?

Indeed removing the spaces work.

It would be a huge help to add this instructions in the README, it will save some hours to much people. I just lost all afternoon after this!

There is documentation at https://www.drupal.org/docs/contributed-modules/drupal-symfony-mailer/ge... → . Anyone can edit it.