Showing your logo in the inbox

Some mail clients display the sender's logo next to the message. That takes configuration, not just a nice template.

What is required

Authentication in order, with DMARC in strict mode. That is the entry condition: without it no logo appears.

What you have to supply

A logo in vector format to precise specifications, published on your domain and referenced in DNS.

What it gives you

Recognition in a list of messages, and a trust signal. It helps most against impersonation: a fake message will not carry your logo.

The expensive part

Some providers also require a registered trademark and an associated certificate. That is what makes it disproportionate for many smaller organisations.

Where to start

Sort out DMARC first. It is worth doing on its own merits, regardless of the logo, and it is the mandatory step anyway.