Email header for a profile picture or avatar?

Question

I am playing around with the python mailjet api, and found that I can set the sender's name so instead of emails showing up from "Info" ([email protected]) I can have them show up from "Carlos". I would also like to add a profile picture like that of Southwest Airlines or Twitter.

Anyone have any idea how I might do that?

I know that if I don't post code then people get angry, so here's some code:

mailjet = Client(auth=(API_KEY, API_PASSWORD), version='v3.1')
data = {
    'Messages': [
        {
            "From": {
                "Email": "[email protected]",
                "Name": "Carlos"
            },
            "To": [
                {
                    "Email": trip.email
                }
            ],
            "Subject": "Subject of the message",
            "TextPart":"This is the body of the message",
            "Headers": {
                    "X-My-Header": "https://www.example.com/profile_pic.png"
            }
        }
    ]
}
mailjet.send.create(data=data)

Answer 1

2022 update: The best method for this is BIMI, Brand Indicators for Message Identification.

BIMI uses DMARC to ensure authenticity and then allows specifying a brand icon to be displayed in email clients. Google has supported it since 2020, but BIMI didn't exist back in 2018 when I composed this original answer.

I don't think there's a specification yet (see the IETF BIMI draft from 2021), so the best resource is the BIMI Group itself.

---

There are two headers out there that may (but probably won't) work for you:

1. X-Face
2. X-Image-URL

Neither has great support. X-Image-URL was supported in Apple Mail until v4.5.

It's not a header, but I think Gravatar is probably the closest thing to what you're looking for. With a Gravatar account, you can post an image to match your email's MD5 hash for various websites and email clients to pick up. There are a few implementations of email client helpers/extensions/add-ons that apply sender email Gravatars to a message, including Thunderbird's Contact Photos add-on, but that doesn't even have broad adoption on Thunderbird, which itself doesn't have broad adoption.

I can't comment on how it's done with Google specifically, but many enterprise systems simply propagate your image from your account profile.

Note that this does introduce a new confidence indicator that can be abused by phishing attacks, though I haven't seen one yet.