Several cloud-based mail providers, chiefly Google and Microsoft, have announced plans to end support for basic authentication for IMAP. Jira needs to be able to support these providers over a modern authentication protocol such as OAuth.
Google has paused their plans to shut off OAuth due to COVID-related impacts on organizations, and will give 12 months advance notice when they set a new timeline.
Jira Cloud also now supports OAuth for Microsoft accounts per
JRACLOUD-73240. Jira Service Management now supports OAuth for Google and Microsoft per JRACLOUD-72590. The remaining ask here is for OAuth with Google/Gmail and the primary Jira mail handler.