Sending Emails As Admin

Consider a scenario where you provide a service based on Syncrify and your users use SyncriBox to send/receive large files from users on the Internet. For example, you have a user whose email address is john.doe@yahoo.com. Assume this user needs to send a large file to jane.doe@gmail.com.

John can use SyncriBox to send a large file and Syncrify will generate an email that is sent to Jane containing a download link. However, if the sender of this email is john.doe@yahoo.com, Google's SMTP server will consider this a forgery because your network is not supposed to send emails where sender belongs to yahoo.com. In more technical terms, SPF as well as DMARC will fail and you risk getting your public IP getting listed on an RBL server.

To solve this problem Syncrify offers an option called Use admin's email as sender available under Email Configuration. When this box is checked, Syncrify will use the administrator's email address in MAIL FROM value of smtp envelope. The actual FROM header is not modified, allowing Jane to see John's address in the email client. By changing the MAIL FROM in the envelope, SPF check won't fail and hence DMARC will pass as well. Check this page for more information about the differences between MAIL FROM in the envelope and FROM header in the email.