After moving email away from your web host, check the host's mail routing setting

The server can believe it is the mail server

cPanel-style hosting has a setting called Email Routing for each domain. It decides whether the server keeps mail for the domain itself or sends it on to another mail server. By default it detects the answer from the domain's MX records, but cPanel's documentation says the detection reads only the local zone file on the server and does no real DNS lookup. If that local copy still lists an MX pointing at the server, the server decides it is the mail server for your domain, even though public DNS, held elsewhere, now sends mail to a new provider.

The result is a split. Outside senders follow public DNS and reach the new provider. Mail sent from the website's own server, or from webmail on the old host, to your own addresses is checked against the local setting first, so it is delivered to a local mailbox, or refused, and never reaches the new mailboxes.

The three settings

Local Mail Exchanger: the server always accepts mail for the domain and delivers it to a local mailbox. cPanel suggests it for domains that use a smart host or a filtering gateway. Backup Mail Exchanger: the server holds mail for the domain until a lower-numbered mail exchanger becomes available. Remote Mail Exchanger: the server refuses mail for the domain and passes everything to the lowest-numbered mail exchanger. After you set a value manually, cPanel says the system does not change it on its own, so a setting left on Local stays on Local for good.

• Local fits only if you really want the server to keep mail.
• Remote fits when another provider holds the mailboxes.
• Automatic depends on the local zone file being right.

How it looks from your side

Typical symptoms are that mail from outside arrives but a contact form, a booking system, a script or a password-reset email sent from your own site to your own address never does. Colleagues sending from the old webmail to each other may find messages land in an old local mailbox nobody reads. The bounce text, if any, may say the mailbox does not exist, because the server is looking for it locally.

• Works from Gmail, fails from the website: suspect routing.
• A bounce that says the address does not exist, though it does at the new provider.
• Messages appearing in an old webmail mailbox.

A safe first investigation

Compare three things without changing any: the MX records shown in the host's Zone Editor for the domain, the MX records that public DNS returns, and the Email Routing setting for the domain. A mismatch between the first two, or Local routing while the mailboxes live elsewhere, is the pattern. cPanel warns that a wrong setting can interfere with the domain receiving mail, so if you are unsure, ask your hosting provider before changing it. Then send a test from the website or webmail to a named address and read the headers of any message that arrives to see which servers handled it.

Fixing it, and the paid outcome

The fix is to set the domain to Remote when mail lives elsewhere, and to make the host's local MX entries match public DNS. Keep the old local mailboxes until you are sure all mail has been collected from them. If you do use a filtering gateway, Local may be correct, and this job does not apply.

The fixed-price job for this is a published test price of £175, not yet tested with buyers, payable after sign-off. Its third acceptance test is the one that matters here: a test sent from your website's host to each named address arrives at the new provider's mailbox, and its headers show the provider's servers rather than a local mailbox. It does not move old messages, and mail that arrives in junk is a separate authentication matter.