diff --git a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
index 01e4eeb7a0..32f152f8ff 100644
--- a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
+++ b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
@@ -13,6 +13,11 @@ final class PhabricatorMailImplementationPHPMailerAdapter
     $this->mailer = new PHPMailer($use_exceptions = true);
     $this->mailer->CharSet = 'utf-8';
 
+    // NOTE: This works around what seems to be a bug in SendGrid, see
+    // D10278. This affects other SMTP mailers too, but as long as they
+    // don't have an opposite bug to SendGrid's bug that should be OK.
+    $this->mailer->Encoding = 'quoted-printable';
+
     // By default, PHPMailer sends one mail per recipient. We handle
     // multiplexing higher in the stack, so tell it to send mail exactly
     // like we ask.