As a starting point, you could try some of the advice offered here: Problem sending email from Microsoft 365
Or documentation also offers some advice: https://docs.pkp.sfu.ca/admin-guide/3.3/en/email
-Roger
PKP Team
As a starting point, you could try some of the advice offered here: Problem sending email from Microsoft 365
Or documentation also offers some advice: https://docs.pkp.sfu.ca/admin-guide/3.3/en/email
-Roger
PKP Team