The best you can hope to do is reduce a small class out of possible errors. But you'll never get a test that can prevent errors like name@gnail.com, name@gmaip.com, nane@gmail.com etc. So is it really worth doing any checks at all?
I have a .blue email address and it's amazing how many sites still won't accept it. I keep a spare Gmail account for these.
> But you'll never get a test that can prevent errors like name@gnail.com, name@gmaip.com, nane@gmail.com etc. So is it really worth doing any checks at all?
You can do quite well at this, if you're willing to not restrict yourself to regexes and commit to some amount of hackery. One system I worked on used a simple regex (just what is described here IIRC - assert the existence of an @ sign), plus did an MX check on the domain, plus warned (not errored) if the domain was within 1 or 2 Levenshtein distance of any of a list of most common email domains (yahoo, gmail, etc). Statistically it seems like we saved people a lot of grief with this simple filtering.
The downvotes are a sign that I did not notice that my reply to the poster was not composed. I got the memo, and will take note from now on, mark my words!
.blue is 11 years old and still has issues. Same with several of the gtlds I have. I had an argument with a major backend email provider recently who refused to open an account for me as my gtld wasn't "valid." (they backed down eventually and fixed their code)
I keep a Gmail for the same reason.
I tried to add a .wiki link to a Reddit profile recently and their filters also say that domain is invalid.
Does this block things like the unconventional Google-filing trick of:
myemail+90sdev@gmail.com
which gives me the “90sdev” tag for my emails, which still go squarely into my “myemail@gmail.com” address? I don’t know what the best route is, but I’ve certainly run into bad validators that block things that otherwise work, and that’s annoying. It seems to me the best thing might be to have a user twice input their address, then have the next step/confirmation done via email.
Documented as "subadressing" in RFC 5233, and the default for both sendmail and postfix, amongst others. As such, often 'accidentially' supported by many mail providers even when undocumented. Google didn't introduce them, nor are they 'unconventional'.
I never get spam that makes it through the default filter, so I am unsure if this works, but I do get zero spam in general since switching off gmail. I like giving silly businesses that ask for my email their business name @ my domain.
Most of the time they're too disinterested to notice. Oil change places always notice for some reason.
I'll look through my spam foldsr tomorrow and see who's been naughty.
Both parts are limited to 7-bit ASCII or a subset thereof. Emojis have to be in punycode. You could theoretically use UTF-7 for the local-part but nothing supports it in practice.
That's the spec, for sure! The domains are converted to punycode, but the usernames? I have no idea what happens to them. My tests showed some providers delivered them, some didn't. I'm sure there are a bunch of people out there using accented characters and CJK etc in their usernames and wondering why it's not going so well...
