Allow customization of assignment email subjects and content

[Kobby-Bawuah]

Problem Statement

Currently, Sentry supports project-wide email subject prefixes via mail:subject_prefix and customizable subject templates for issue alert emails via mail:subject_template. However, assignment activity notifications use a fixed subject format that cannot be customized.

This limitation prevents teams from distinguishing assignment notifications by environment or other context (e.g., staging vs. production) at a glance.

Solution Brainstorm

Extend the existing mail:subject_template functionality (or introduce a similar option) to support assignment emails.

Product Area

Alerts

[linear]

ENG-5805

[getsantry]

Assigning to @getsentry/support for routing ⏲️

[getsantry]

Routing to @getsentry/product-owners-alerts for triage ⏲️

[saponifi3d]

Thanks for this feature request @Kobby-Bawuah!

I think this feature makes a lot of sense, i'll add it to our backlog to investigate and think about. Just a heads up, that this area is pretty complicated and is also in a bit of flux -- so it might be a little bit until we can get to it. Feel free to ping here for any updates or to bring it back to the forefront for us!