From 6af415e0603173672717a2e11ddd100027fd6fe7 Mon Sep 17 00:00:00 2001
From: Antoine Nguyen <tonio@ngyn.org>
Date: Sun, 27 Jul 2025 12:51:37 +0200
Subject: [PATCH] Added missing EHLO before auth attempt

---
 modoboa/lib/smtp_backend.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/modoboa/lib/smtp_backend.py b/modoboa/lib/smtp_backend.py
index 88a86776d..234ff12d4 100644
--- a/modoboa/lib/smtp_backend.py
+++ b/modoboa/lib/smtp_backend.py
@@ -36,6 +36,7 @@ class OAuthBearerEmailBackend(EmailBackend):
                 self.connection.starttls(context=self.ssl_context)
             if self.username and self.password:
                 token = oauth2.build_oauthbearer_string(self.username, self.password)
+                self.connection.ehlo(DNS_NAME.get_fqdn())
                 self.connection.docmd("AUTH", f"OAUTHBEARER {token.decode('utf-8')}")
             return True
         except OSError: