The integration is well done, CHECK seems like IMAP is working, the leaves are coming.
What else do you need to indicate if the leaves were sent via SMTP?
I tried submitting a different port and ticking the TLS checkbox, otherwise gmail support write what you can tweak if the server allows it.
ale, the leaves are not now vіdsilayutsya
https://prnt.sc/w7bxyw, wanting to add a plus sign in the name of the ruled leaves.
and in "my submissions" put on the administrative sheets there is a sign of "attachment"
https://prnt.sc/w7buvywhy?