Have you ever received an email that looked like it was from someone you know, but turned out to be fake? This is a common tactic known as phishing, where spammers and scammers forge emails to appear as though they’re coming from legitimate senders.
To help combat phishing, some ISPs now provide more transparency about the sender. If the server sending the email isn't authorized by the domain in the "From:" address, the recipient may see a "via" or "on behalf of" message, signaling that the email may not be from a verified source.

Why Are My Legitimate Emails Showing "via bnc3.mailjet.com"?
When you send emails through Mailjet, they are delivered via Mailjet's servers. If you haven’t authorized Mailjet as an approved sender for your domain, this “via” message will appear to your recipients, even if your emails are legitimate.
How Do I Authorize Mailjet as a Legitimate Sender?
To authorize Mailjet and prevent the "via" message from appearing, you need to set up SPF and DKIM authentication for each domain you use to send emails. This process verifies that Mailjet is allowed to send emails on your behalf.
What If I’m Using Gmail, Yahoo, Hotmail, or Another Free Webmail Service?
Unfortunately, you cannot modify the SPF and DKIM records for free webmail services like Gmail, Yahoo, or Hotmail. For better email delivery and reputation, it’s strongly recommended to use an email address tied to your website’s domain. Setting up custom SPF and DKIM records for your domain will improve your email authentication, helping ensure your emails reach your recipients' inboxes.
Check out the following article on the Gmail and Yahoo updates made in 2024 to stay compliant with evolving standards and improve your sender reputation and deliverability.