diff --git a/src/applications/config/option/PhabricatorPHPMailerConfigOptions.php b/src/applications/config/option/PhabricatorPHPMailerConfigOptions.php
--- a/src/applications/config/option/PhabricatorPHPMailerConfigOptions.php
+++ b/src/applications/config/option/PhabricatorPHPMailerConfigOptions.php
@@ -44,6 +44,23 @@
       $this->newOption('phpmailer.smtp-password', 'string', null)
         ->setMasked(true)
         ->setDescription(pht('Password for SMTP.')),
+      $this->newOption('phpmailer.smtp-encoding', 'string', '8bit')
+        ->setSummary(pht('Configure how mail is encoded.'))
+        ->setDescription(
+          pht(
+            "Mail is normally encoded in `8bit`, which works correctly with ".
+            "most MTAs. However, some MTAs do not work well with this ".
+            "encoding. If you're having trouble with mail being mangled or ".
+            "arriving with too many or too few newlines, you may try ".
+            "adjusting this setting.\n\n".
+            "Supported values are `8bit` (default), `quoted-printable`, ".
+            "`7bit`, `binary` and `base64`.\n\n".
+            "The settings in the table below may work well.\n\n".
+            "| MTA | Setting | Notes\n".
+            "|-----|---------|------\n".
+            "| SendGrid via SMTP | `quoted-printable` | Double newlines under ".
+            "`8bit`.\n".
+            "| All Other MTAs | `8bit` | Default setting.")),
     );
   }
 
diff --git a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
--- a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
+++ b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerAdapter.php
@@ -13,10 +13,8 @@
     $this->mailer = new PHPMailer($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';
+    $encoding = PhabricatorEnv::getEnvConfig('phpmailer.smtp-encoding', '8bit');
+    $this->mailer->Encoding = $encoding;
 
     // By default, PHPMailer sends one mail per recipient. We handle
     // multiplexing higher in the stack, so tell it to send mail exactly
diff --git a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerLiteAdapter.php b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerLiteAdapter.php
--- a/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerLiteAdapter.php
+++ b/src/applications/metamta/adapter/PhabricatorMailImplementationPHPMailerLiteAdapter.php
@@ -15,7 +15,9 @@
     require_once $root.'/externals/phpmailer/class.phpmailer-lite.php';
     $this->mailer = new PHPMailerLite($use_exceptions = true);
     $this->mailer->CharSet = 'utf-8';
-    $this->mailer->Encoding = 'quoted-printable';
+
+    $encoding = PhabricatorEnv::getEnvConfig('phpmailer.smtp-encoding', '8bit');
+    $this->mailer->Encoding = $encoding;
 
     // By default, PHPMailerLite sends one mail per recipient. We handle
     // multiplexing higher in the stack, so tell it to send mail exactly
diff --git a/src/docs/user/configuration/configuring_outbound_email.diviner b/src/docs/user/configuration/configuring_outbound_email.diviner
--- a/src/docs/user/configuration/configuring_outbound_email.diviner
+++ b/src/docs/user/configuration/configuring_outbound_email.diviner
@@ -12,7 +12,7 @@
 |---------|-------|------|---------|-------|
 | Mailgun | Easy | Cheap | Yes | Recommended |
 | Amazon SES | Easy | Cheap | No | Recommended |
-| SendGrid | Easy | Cheap | Yes | |
+| SendGrid | Medium | Cheap | Yes | Discouraged (See Note) |
 | External SMTP | Medium | Varies | No | Gmail, etc. |
 | Local SMTP | Hard | Free | No | (Default) sendmail, postfix, etc |
 | Custom | Hard | Free | No | Write an adapter for some other service. |
@@ -34,6 +34,11 @@
 not. For more information on using daemons, see
 @{article:Managing Daemons with phd}.
 
+**Note on SendGrid**: Users have experienced a number of odd issues with
+SendGrid, compared to fewer issues with other mailers. We discourage SendGrid
+unless you're already using it. If you send to SendGrid via SMTP, you may need
+to adjust `phpmailer.smtp-encoding`.
+
 = Basics =
 
 Regardless of how outbound email is delivered, you should configure these keys
@@ -83,6 +88,9 @@
 how to configure it, this option is straightforward. If you have no idea how to
 do any of this, strongly consider using Mailgun or Amazon SES instead.
 
+If you experience issues with mail getting mangled (for example, arriving with
+too many or too few newlines) you may try adjusting `phpmailer.smtp-encoding`.
+
 = Adapter: SMTP =
 
 You can use this adapter to send mail via an external SMTP server, like Gmail.
@@ -97,6 +105,9 @@
   - **phpmailer.smtp-password**: set to your password used for authentication.
   - **phpmailer.smtp-protocol**: set to `tls` or `ssl` if necessary. Use
     `ssl` for Gmail.
+  - **phpmailer.smtp-encoding**: Normally safe to leave as the default, but
+    adjusting it may help resolve mail mangling issues (for example, mail
+    arriving with too many or too few newlines).
 
 = Adapter: Mailgun =