Why it is impossible to use a public domain like Yahoo or Gmail as a Sherweb email address


This guide will tell you why you cannot use a public domain like Yahoo or Gmail as your email address with Sherweb.

Applicable to

All Sherweb hosted Exchange accounts.


The issue is not so much sending something as any domain name you desire. It is mostly because of the receiving mail servers that will validate with public mail server addresses of the public domains1 like Gmail, Hotmail, AOL, Rogers, etc (through a DNS query) that the relay from Sherweb hasn't come from the smtp of those servers.

This isn't always a problem. However, more and more firewall and spam filters will block these relays and create an internal blacklist of smtp IPs that will allow forwarding using public or popular domain names like Hotmail, Gmail, Yahoo, AOL etc.

This becomes a problem for us since mail administrators will not block all Hotmail, Yahoo, AOL, Rogers, etc. emails and mark them as spam. Instead, they will block the senders. The industry as a whole is trying to adopt techniques to stop spammers and this is a very effective strategy, because shutting down the sending SMTP IP's shuts down the spammers.

It will also cause problems and conflicts with users who want to use the same public domain. We understand your desire to have us pass the public domain through our SMTP, but unfortunately we won't be able to remove the public domain from our list of disallowed SMTP domains.


If you need further assistance, please do not hesitate to contact us.

Foot notes

  1. Public domains: domains that are widely recognized as an email provider.