minor #9762 Creating Messages link seems to be broken (zspine)

This PR was submitted for the 3.4 branch but it was merged into the 2.7 branch instead (closes #9762).

Discussion
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Creating Messages link seems to be broken

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Commits
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2ea1f49 Creating Messages link seems to be broken

Author: javiereguiluz

email.rst

@@ -169,7 +169,7 @@ Learn more
     email/*
 
 .. _`Swift Mailer`: http://swiftmailer.org/
-.. _`Creating Messages`: http://swiftmailer.org/docs/messages.html
+.. _`Creating Messages`: https://swiftmailer.symfony.com/docs/messages.html
 .. _`Mandrill`: https://mandrill.com/
 .. _`SendGrid`: https://sendgrid.com/
 .. _`Amazon SES`: http://aws.amazon.com/ses/