Frequently Asked Questions
Why do SMTP newsletters get blocked by Gmail, Yahoo, and other email providers?
Large providers look closely at sending volume, sender reputation, authentication, and unusual bulk activity. If many messages are sent at once from a standard office mail server, they can be filtered or blocked even when the content is harmless.
Mail Designer 365 explains this provider behavior in its article about the disadvantages of SMTP sending.
Mail Designer 365 explains this provider behavior in its article about the disadvantages of SMTP sending.