v1.5.11

Add Symfony SendGrid Mailer bridge as a Composer runtime dependency.

Sendgrid Callback 1.5.10

Sendgrid Callback 1.5.10 carries Mautic email attribution through API custom arguments and SMTP metadata, honors the blocked-event switch, returns HTTP 503 for database failures and prevents repeated callback DNC duplicates. Unsubscribes are not downgraded by later bounces.

Verified with 13 tests per version, fresh kernels and native database callbacks on Mautic 5.2.10, 6.0.9, 7.1.3 and 7.2.0. Live SendGrid delivery was not exercised. See LINEAGE_AUDIT.md for the SES inheritance audit.

v1.0.0

Initial public release of SendGrid callback plugin for Mautic 5/6/7.