Advanced Notice: Retirement of legacy hostnames/service URLs

Now that the Refresh programme has concluded with all NHSmail mailboxes migrated to Exchange Online, we are writing to give notice of the retirement of several legacy hostnames/service URLs within the environment.


These hostnames will be permanently disabled on 07 September 2021. Any mail-enabled applications or devices that authenticate with NHSmail using any of the above hostnames will be unable to connect after this date.

What action do I need to take?

Organisations where local applications or devices are configured to use a legacy hostname address will need to update configurations to point directly to the one of the hostnames detailed below, in order to bypass legacy NHSmail infrastructure due to be decommissioned.

POP/IMAP/SMTP hostnames


Purpose Hostname Port Encryption

Auth Required


Receiving Email 993 SSL Yes


Receiving Email 995 SSL


SMTP* Sending Email
587 TLS


*When configuring SMTP, for any high-sending accounts it is recommended that is used due to Exchange Online sending limitations. Please visit the High-Sending Accounts guidance for further information.

Legacy & Exchange ActiveSync hostnames

Legacy Hostname

New Hostname

Further details can be found on the Application account guidance page

Why do we need to make this change?

Now that the NHSmail service has fully migrated to Exchange Online, work is underway to decommission legacy Exchange infrastructure.

A temporary solution was previously implemented to ensure accounts could connect to Exchange on premise or Exchange Online (regardless of the migration status). Organisations should now update local configurations to use the appropriate hostname detailed above.

If an application is using hard coded IP addresses, please ensure this is updated to use a hostname as per best practice.


Please contact the NHSmail helpdesk if you have any queries.

A further reminder communication will be sent to organisations with affected accounts over the coming weeks.

Best wishes,

NHSmail Team

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