This might mean {{ contact.email }}

• is not a valid email address, or
• doesn't exist, or
• its mail server refuses your email

The email is automatically deleted in 7 days.

Please consider the following options:

1. If the email is not spam, you can create a filter to explicitly allow all emails from SimpleLogin.
   
2. If this email is indeed spam, it means your alias {{ alias.email }} is now in the hands of a spammer. You can either disable the alias or block the sender if they send too many spams.