If you try to add a Google Workspace mailbox to a sequencer by uploading an SMTP username and password, the connection fails with an error like 535-5.7.8 Username and Password not accepted. This is expected, and it isn't a problem with your mailbox.
Why the password upload fails
Google does not allow plain password authentication for Workspace accounts. Sequencers therefore cannot connect a Google Workspace mailbox from an SMTP/IMAP credentials list the way they can with a standard SMTP mailbox.
How to connect a Google Workspace mailbox
In your sequencer, choose the Google / Gmail connection option rather than the generic SMTP or CSV upload option.
Sign in with the mailbox address when prompted, and authorise the sequencer.
You have full administrator access to your Google Workspace account. The mailbox password and the one-time code needed to complete sign-in are both available in your Maildoso dashboard.
Repeat for each mailbox, or use your sequencer's bulk Google connection flow if it offers one.
Connecting many mailboxes
Connecting dozens of Workspace mailboxes one by one is slow. Most sequencers let you connect several at a time through the Google option. If yours does not, or the flow keeps failing part-way through, contact us with the list of mailboxes and the sequencer you're using and we'll look at it with you.
What about SMTP mailboxes?
Standard Maildoso SMTP mailboxes are different — those do connect with a username and password, and can be uploaded to your sequencer as a credentials file. If an SMTP mailbox is rejected with a 535 error, the credentials themselves are worth re-checking before anything else.
A note on DKIM and SPF warnings
After connecting, some sequencers display a warning that DKIM, SPF, or DMARC is "not configured". Authentication for your Maildoso domain is set up and managed for you, and these warnings can generally be ignored — they reflect what the checker can see, not what is actually published.
If a mailbox still won't connect after following the steps above, contact us and we'll review your specific case.