Images in the subject line

I’ve seen this trick used by a few senders recently, with varying effectiveness.

Where do they get these pictures?

While you can scatter any images you like across the body of your message, the subject line is limited to just text. But “text” is more than just “a, b, c” – using RFC 2047 encoding you can use any character you like, including many tiny pictures.

⛄ 💰 🐘 ✈ 🎁 ☂


Experian, Vertical Response and Bronto all have some interesting things to say about the effectiveness of using these.

Finding the right glyph can be tricky. Macs have a fairly decent glyph search engine (under Edit > Special Characters… in most applications) while Windows has a fairly mediocre one (Start > All Programs > Accessories > System Tools > Character Map > Advanced View). Both are missing some useful features, though, so I put together something better. lets you search for glyphs by name. It’ll tell you about related glyphs (“helicopter” and “airplane”, or “package” and “wrapped present”) which can help you find the right image when you don’t know it’s name. And, once you’ve chosen a glyph, it shows how to use it in various encodings (if you’re using a GUI tool or a web form to compose your emails you can probably just copy and paste, but it’s handy for manually editing messages when your composition tool isn’t unicode-friendly).

Will all your recipients be able to see these glyphs? All mail clients support utf-8 text and this sort of encoding so the only issue is whether the recipient has a font installed with the glyph in it. That’s operating system specific, rather than depending on the web browser or mail client, so if you want to test – and you probably should – you can get away with just Windows and OS X for desktop, iOS and Android for mobile.

Have fun! But don’t overdo it.

1 comment

  1. Elibert Beukens says


    Nice article! About three weeks ago i also wrote a message on the E-difference Blog in Dutch about the use of unicode symbols in subjectlines. The name of the article: ☛De ★nieuwe★ manier om op te vallen in de ✉. We ♥: But i was not aware of the nice functionality search for glyphs by name.

    Greetings Elibert


Your email address will not be published. Required fields are marked *

  • DNS problems

    Hurricane Electric had a significant outage of their authoritative DNS servers this morning, causing them to return valid responses with no results for all(?) queries. This will have caused delivery problems for any mail going to domains using DNS - which will include some of their colocation customers, as well as users of their free services - but also will have caused reverse DNS to fail for most servers hosted by Hurricane Electric worldwide, so if any of your mail is being sent from HE hosted machines you may have seen problems. (We're HE customers so we noticed. Still happy with them as a vendor.)No Comments

  • DNS issues

    If you're sending email from any address beginning with a 65 - in - it's possible you'll see some delivery problems. Something appears to be broken with dnssec signatures for the reverse DNS zone, leading queries for reverse DNS to fail for anyone using a dnssec aware DNS resolver (which is almost everyone).1 Comment

  • Our green bar certificate is going away

    Later today we'll be switching from an Extended Validation ("green bar") SSL certificate to a Domain Validation certificate. This isn't exactly a planned change but I'm waiting for responses from Comodo before I go into it too much. I'll share some more details next week.3 Comments