Email signatures

I’ve had a spate of emails land in my many inboxes recently with obnoxious and unnecessary signatures attached, so I though I’d spell out the best practices.

Don’t put images anywhere in the signature, and refrain from putting them in the email body at all if you can avoid it. They frequently can’t even be rendered on mobile devices, require additional data in the envelope as well as the binary data for the images, and can cause problems with email indexing services — I know of a popular email text indexer that will stop indexing at the first attachment section that contains base64 encoded binary data.

The same goes for HTML really and other markup. Use it sparingly in the message body and signature since it causes overhead. Well behaved email systems will always send the plain text representation for agents that can’t render the markup. Really that plain text is all you really want.

Don’t sign off email with much more than you’d sign off a hand-written letter. You don’t need screeds of legalese telling me that if I’m not the intended recipient I should delete it immediately, or that I shouldn’t print it out to save trees. I’ll do what I damn well please with it if you send it to me, including reading it and printing it out for my reference.

All you need to sign off with is your name, who you work for, and one or more alternative means to get in touch. Maybe a phone number or postal address. That’s it, all plain text. No images of your company logo and as little extra formatting as you can get away with.

Don’t set your email client to add the signature at the end of all replies as well. Send the full signature once, sign off with just your name afterwards on subsequent replies.

The overriding thing to remember is that email transport systems were overwhelmingly designed to efficiently send plain text. That you can now add markup and images just adds extra, hard to compress in the image case, hard to index in the markup case, data that is wasteful at both transmission and storage time.

Just stick to the words and let a link to your website do anything fancier, especially in the signature.