Email migration service interruptions

Due to the ongoing migration of our email servers on Cluster A, some email users may experience SSL connection errors when accessing our Hosted Email IMAP servers via email client. This interruption does not impact users accessing email via webmail. 

Service impact 

A small percentage of users who connect via their email client may experience security exception warnings. Users connecting on Cluster A with a non-standard hostname not protected by our white label process may encounter the notice on their device.

Email clients may display notifications regarding verification or certificates, which can happen on any client such as Thunderbird, Spark, Mail, or Outlook. Such messages may say, “Cannot verify server identity” or, “The server you are connected to is using a security certificate that cannot be verified”. 

We’ve captured some example warnings from iOS and Outlook:


Impacted users who encounter a warning can decide to continue by performing one of the following:

This error may also occur when users are running software that has not been updated, missing current valid root certificates. Links to the most recent versions from Apple and Android devices are available in the external resources section.

We recommend you review email client configuration/setup with your customers by ensuring they connect via secured address to help prevent this issue. Our addresses of or will ensure customers avoid these exceptions. They may also use any address you’ve provided us for white labelling. We are taking steps to mitigate the effects and are notifying affected resellers directly as we identify affected users. 

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Migration timeline

This is our schedule for the third phase of Cluster A email migration.





Jan 12 - Mar 15

Finalize IMAP migration 

Accessibility to Webmail/IMAP/POP, minimal impact



Jan 12 - Jan 30

Finalize metadata migration

User metadata, no impact expected


Jan 12 - Feb 15

Finalize data migration

User mail-store data, no impact expected

In progress

Jan 12 - Mar 15

Finalize custom environment migrations

Migrating to new load balancer, minimal impact

Delayed: vendor issue

Jan 12 - Feb 28

Managing new outbound relays

Outbound email sending, minor deliverability issues as external vendors update their records

In progress

Feb 1 -

Feb 28

Preparing for decommissioning

Legacy hardware, no impact expected

In progress

External resources

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