Erik HeimdalEH
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Unusual email addresses

1 min read

The email format supports a broader range of addresses than commonly used. In this project, I registered some unusual ones I came across.

Tools Used

Method

Longest Email Address

I started by researching the maximum number of characters allowed in an email address. According to Stack Overflow, it can be no longer than 320 characters, in the format [64]@[255].

I chose π (pi) for its unlimited pattern, selecting the first ~300 digits as my new email address. After registering the domain and sending an email through Gmail, it went through successfully:

3.1415926535897932381146264338327950288419716939937510582097494459@230781640628620899862803482534211706798214808651328230664709384.460955058223172535940812848111745028410270193852110555964462294.895493038196442881097566593344612847564823378678316527120190914.5648566923460348610454326648213393607260249141273724587006.tk

However, the username was 66 characters, 2 characters longer than expected. The maximum valid domain length is actually 253 characters, as verified by Cloudflare, not the previously stated 255.

Adjusting for these parameters, I extended the username part to an upper limit of 998 characters and minimized dots to make room for more π-decimals. The final email address was 1,252 characters long, containing the first 1,245 decimals of π.

Shortest Email Address

The minimum length for an email address is six characters, made up of [username]@[domain].[top-level-domain]. The shortest practical top-level domain has two characters.

Unfortunately, all single-character domains were either taken or prohibitively expensive. As a workaround, I registered a domain using a non-ASCII character (ä), encoded as xn--4ca in Punycode but appearing as a single character in browsers. I successfully registered this for free and set up the MX-records. The resulting email address was six characters long:

e@ä.gq

Emoji Email Addresses

Exploring further, I discovered it was possible to register domains containing emojis. While many single-emoji domains were taken, I secured several unique addresses:

mail@📬.ml
erik@👨‍💻.cf
allah@🛐.ml
steffe@🇸🇪.gq
work@📄.tk

Weird Email Addresses

I experimented with unicode alternatives to otherwise illegal domain name characters, resulting in:

!!!!!!!!!@ǃǃǃǃǃǃǃǃǃ.cf
#$&?@ǃ∗٪.ga

Result

World's Longest Email Address (1,252 characters)

31415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679821480865132823066470938446095505822317253594081284811174502841027019385211055596446229489549303819644288109756659334461284756482337867831652712019091456485669234603486104543266482133936072602491412737245870066063155881748815209209628292540917153643678925903600113305305488204665213841469519415116094330572703657595919530921861173819326117931051185480744623799627495673518857527248912279381830119491298336733624406566430860213949463952247371907021798609437027705392171762931767523846748184676694051320005681271452635608277857713427577896091736371787214684409012249534301465495853710507922796892589235420199561121290219608640344181598136297747713099605187072113499999983729780499510597317328160963185950244594553469083026425223082533446850352619311881710100031378387528865875332083814206171776691473035982534904287554687311595628638823537875937519577818577805321712268066130019278766111959092164201@989380952572010654858632788659361533818279682303019520353018529.689957736225994138912497217752834791315155748572424541506959508.295331168617278558890750983817546374649393192550604009277016711.3900984882401285836160356370766010471018194295559619894676.tk

World's Shortest Email Address (6 characters)

e@ä.gq

Emoji Email Addresses

mail@📬.ml
erik@👨‍💻.cf
allah@🛐.ml
steffe@🇸🇪.gq
work@📄.tk

Other Weird Email Addresses

!!!!!!!!!@ǃǃǃǃǃǃǃǃǃ.cf
#$&?@ǃ∗٪.ga

Most of these email addresses were registered and configured for email forwarding to me, but as I did not renew the domains I no longer own them as of 2021.