# Pull Request Template
## Description
This PR adds IMAP authentication mechanism selection to Chatwoot's email
inbox configuration. Users can now choose between 'plain', 'login', and
'cram-md5' authentication methods when configuring IMAP settings,
providing flexibility for different email providers that require
specific authentication types.
https://github.com/chatwoot/chatwoot/issues/8867
The implementation includes:
- Frontend dropdown with numeric keys (1, 2, 3) matching SMTP auth style
- Backend API validation for allowed authentication mechanisms
- Consistent 'cram-md5' format throughout the codebase
- Updated IMAP service to handle different auth types properly
This feature maintains consistency with existing SMTP authentication
options and follows the established UI/UX patterns in the application.
## Type of change
Please delete options that are not relevant.
- [x] New feature (non-breaking change which adds functionality)
- [ ] Bug fix (non-breaking change which fixes an issue)
- [ ] Breaking change (fix or feature that would cause existing
functionality not to work as expected)
- [ ] This change requires a documentation update
## How Has This Been Tested?
### Manual Testing:
- Tested in Docker environment
- Verified IMAP auth dropdown appears in inbox settings
- Confirmed all three auth mechanisms (plain, login, cram-md5) can be
selected and saved
- Tested API validation by attempting to save invalid auth mechanisms
### Automated Testing:
- Updated existing IMAP service tests to use consistent lowercase values
- Updated API controller tests for authentication parameter handling
- All tests pass locally with the new changes
### Test Configuration:
- Tested with both new and existing inbox configurations
## Checklist:
- [x] My code follows the style guidelines of this project
- [x] I have performed a self-review of my code
- [x] I have commented on my code, particularly in hard-to-understand
areas
- [x] I have made corresponding changes to the documentation
- [x] My changes generate no new warnings
- [x] I have added tests that prove my fix is effective or that my
feature works
- [x] New and existing unit tests pass locally with my changes
- [x] Any dependent changes have been merged and published in downstream
modules
## Additional Notes
- This feature is backward compatible and doesn't break existing IMAP
configurations
- The 'cram-md5' format is used consistently throughout (UI, API,
storage, services)
- Net::IMAP compatibility is maintained by converting to 'CRAM-MD5'
internally
- Follows the same pattern established by SMTP authentication
configuration
---------
Co-authored-by: João Santos <joao.santos@madigital.eu>
Co-authored-by: Sony Mathew <sony@chatwoot.com>
This PR limits IMAP email fetching to 500 messages per sync run to avoid
expensive/long-running mailbox scans. It also filters out
already-imported emails and Chatwoot-generated notification emails
during the header fetch phase, before fetching full email bodies,
reducing unnecessary IMAP work.
Fixes #CW-7001 (issue) :
https://linear.app/chatwoot/issue/CW-7001/emails-not-syncing
## Notion document
https://www.notion.so/chatwoot/Email-IMAP-Issue-30aa5f274c928062aa6bddc2e5877a63?showMoveTo=true&saveParent=true
## Description
PLAIN IMAP channels (non-OAuth) were silently retrying failed
authentication every minute, forever. When credentials are
wrong/expired, Net::IMAP::NoResponseError was caught and logged but
channel.authorization_error! was never called — so the Redis error
counter never incremented, reauthorization_required? was never set, and
admins were never notified. OAuth channels already had this handled
correctly via the Reauthorizable concern.
Additionally, Net::IMAP::ResponseParseError (raised by non-RFC-compliant
IMAP servers) was falling through to the StandardError catch-all,
flooding
Estimated impact before fix: ~70–75 broken IMAP inboxes generating
~700k–750k wasted Sidekiq jobs/week.
## Type of change
- [ ] Bug fix (non-breaking change which fixes an issue)
## Checklist:
- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented on my code, particularly in hard-to-understand
areas
- [ ] I have made corresponding changes to the documentation
- [ ] My changes generate no new warnings
- [ ] I have added tests that prove my fix is effective or that my
feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged and published in downstream
modules
