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Allow "external" email addresses for a local domain

Wayne Herbert shared this idea 6 months ago
Needs Review

I have a domain, call it "" on a shared CPanel server. This domain has about 10 email addresses associated with it.

I am moving two of those email addresses to an Exchange server, let's say "" and "". The rest of the email addresses will remain on the CPanel IMAP server.

This is easy to do on the Exchange side of things. My Exchange server becomes the authoritative server in the MX records. Exchange server has a relay feature which allows all email addresses not registered in Exchange to be forwarded to an external email server.

So... jack and jill get handled by the Exchange server while all other flapdoodle email addresses are forwarded to Works great.

Here's the problem. If someone on the CPanel IMAP server, let's say ralph@flapdoodle,org, sends an email to jack or jill, the email is handled locally so no email ever gets sent out to the Exchange server. The mail is delivered to the local mailbox.

I've got a workaround that allows me to auto forward jack's email to "".

But what would be real useful is the ability to mark a local domain email address as "external" so that the email server would send the email instead of processing it internally.

Thank you.

Replies (4)


Does it not work if you set the domain's routing to "Remote Mail Exchanger"? That would create a bit more traffic for Jack/Jill e-mails, but it should work - at least for now.

I on the other hand would be interested in possibly seeing Exchange's Relay feature implemented in cPanel as well so that if most accounts are on the cPanel server it would go there first.

Or having "External" accounts marked for relay instead of everything that isn't found. That way it would keep working with external spam filters since there isn't a catch-all.

An expansion of the "external" e-mail address proposed here would maybe be best where you can add the e-mail server's IP address/domain name that the e-mail for this account should be relayed to. Like - for this e-mail use this server as MX to relay to.

Then everyone can use a different e-mail service ;-)

I see how that could be very useful for some domains we have where a couple people use huge e-mail accounts and others not.


Perhaps I don't understand how "Remote Mail Exchanger" works but the description in CPanel (The server will not accept mail for this domain. The system sends all mail for this domain to the lowest numbered mail exchanger) suggests that the local CPanel server will never accept mail if I use this setting and forward the emails to my Exchange server.

So... in Exchange I've got two domain email accounts setup. All others continued to be managed by my CPanel email service. Any emails not listed in Exchange are automatically relayed to a specified external server, which, in this case, would be the same CPanel email server. It would seem that this would create a perpetual loop, with CPanel server forwarding an email address to Exchange and Exchange immediately forwarding it back.

Again, perhaps I misunderstand how "Remote Mail Exchanger" works.

1 may be right with the "Remote Mail Exchanger" setting. Haven't tested it and didn't read that part in the documentation since years, just found that I needed to set it to make cPanel ignore local accounts and use the MX records of the domain instead (ran across that with external DNS where external e-mail worked, but other users on the server kept delivering locally), and existing accounts stayed on the server after switching to remote. Never tried to see if it actually refuses to accept e-mails...and does it relay them?

Maybe you can try or someone from cPanel can confirm what that setting actually does... ?


Perhaps CPanel can comment and confirm the operation of "Remote Mail Exchanger". In addition to a shared CPanel email server and Exchange email server, I'm using a 3rd party spam filtering service. So, my MX records point to the spam filtering service, its delivery server is my Exchange server, and Exchange auto relays all email addresses not present in Exchange, including 3 more hosted subdomains. I've had my hands full with SPF records, conflicting CNAME autodiscover records, never mind configuring Exchange for multiple domains, limiting IP addresses, and turning off M365 spam checking. I know just enough to be dangerous.

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