If you use a Gmail account for SMTP server, you will not be able to send mail until you do the following: sign in to the Gmail account you use via its standard web interface and confirm any verification questions about the ONLYOFFICE™ access attempt to the account, in case there are some.{0}We recommend using ports 587 or 25 for the email messages to be sent, as other values might prevent the SMTP from the correct work.