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If someone's valid email address [*\"32f2@13.31.43.11 they are up to no good and I don't want them as my customer. Also, according to the standard email addr

by sly010 10y ago

If someone's valid email address [*\"32f2@13.31.43.11 they are up to no good and I don't want them as my customer. Also, according to the standard email addresses supposed to be case sensitive, since the username part refers to a unix user and unix is case sensitive. I work with a lot of email address lists originally collected on paper and of course noone knows that. So as bad as it sounds, part of my sanitation process is to lowercase everything. Noone ever complained. What the standard says and what people actually do is very different.

AgentME 10y ago
Is it specifically the [, *, \, " symbols on the left that you're calling out, the presence of numbers on the right side, the presence of multiple periods on the right side, the lack of letters on the right side, or just the lack of non-numerics on the right side? I don't think most of those rules are needed technically; I wouldn't be surprised if at least one of those rules matches someone reading this comment thread. Any one of those individually seems like a strange minor reason to pre-emptively ban a customer if it doesn't necesarrily cause technical problems. If it's only people hitting multiple of those conditions, then maybe you could use a scoring function that only rejects users that meet multiple conditions? If the reason for the validation is a character judgment instead of a technical limit, then you could add more conditions too. People with email addresses that contain accented characters probably don't even speak the same language as you, so you could save yourself some headaches by marking those invalid. If you don't like leetspeak, then I think banning the letter "x" could be a good move too on average. "+" is used by a lot of people who want to trace whoever you might be selling your email lists to, so you could ban them before they blow the whistle on anything. Email addresses containing references to political candidates probably aren't owned by savory characters, so you could mark those as invalid too... Now that I think about it, since it's not for technical reasons, then none of this is really specific to emails. You could run passwords and other user content through this validation too. If the restrictions aren't for technical reasons, then they're just arbitrary tools for blocking users. Sorry for ranting a bit. I'm just tired of how often I get mystery validation errors from services because something stupid like that it turned out they thought that english works that happen to be sql keywords like "insert" shouldn't be allowed in the subject field, or my friend with an apostrophe in his name repeatedly being turned away from software telling him his name is invalid, and the idea that these rules could be in place just to cause people like us this annoyance ticked me off.
zeveb 10y ago
> If someone's valid email address > [*\"32f2@13.31.43.11 > they are up to no good Well, that one in particular, perhaps — but what about "sam & jill"@ourfamily.invalid? What about john(for sly010)@nowhere.invalid? > Also, according to the standard email addresses supposed to be case sensitive, since the username part refers to a unix user and unix is case sensitive. The local-part doesn't refer to a 'Unix user'; it is what it says on the tin: the local part. It's up to the receiving server to determine what it wants to do with case. It's the duty of other servers to preserve the email address as transmitted. > I work with a lot of email address lists originally collected on paper and of course noone knows that. So as bad as it sounds, part of my sanitation process is to lowercase everything. I might use the email address as given, and if that bounces try lowercasing. I don't know of anywhere that has case-sensitive names, but it's conceivable.
- sly010 10y ago
  I am all for doing things by standards, but to me this is de facto. No one uses case sensitive emails. If they did all sorts of weird things would happen: People couldn't log in, but other people could. There would be multiple accounts when there should be only one, etc. You would have to store every email in original format and in some canonical format for uniqueness, etc. It's a nightmare. If I had to guess the main reason this apocalypse is not happening already is because by default mysql indexes are case insensitive, so dude@dude.com is the same as dude@DUDE.com, so people who use mysql never realize this being an issue.

by sly010 10y ago

AgentME 10y ago

Is it specifically the [, *, \, " symbols on the left that you're calling out, the presence of numbers on the right side, the presence of multiple periods on the right side, the lack of letters on the right side, or just the lack of non-numerics on the right side? I don't think most of those rules are needed technically; I wouldn't be surprised if at least one of those rules matches someone reading this comment thread. Any one of those individually seems like a strange minor reason to pre-emptively ban a customer if it doesn't necesarrily cause technical problems. If it's only people hitting multiple of those conditions, then maybe you could use a scoring function that only rejects users that meet multiple conditions? If the reason for the validation is a character judgment instead of a technical limit, then you could add more conditions too. People with email addresses that contain accented characters probably don't even speak the same language as you, so you could save yourself some headaches by marking those invalid. If you don't like leetspeak, then I think banning the letter "x" could be a good move too on average. "+" is used by a lot of people who want to trace whoever you might be selling your email lists to, so you could ban them before they blow the whistle on anything. Email addresses containing references to political candidates probably aren't owned by savory characters, so you could mark those as invalid too... Now that I think about it, since it's not for technical reasons, then none of this is really specific to emails. You could run passwords and other user content through this validation too. If the restrictions aren't for technical reasons, then they're just arbitrary tools for blocking users. Sorry for ranting a bit. I'm just tired of how often I get mystery validation errors from services because something stupid like that it turned out they thought that english works that happen to be sql keywords like "insert" shouldn't be allowed in the subject field, or my friend with an apostrophe in his name repeatedly being turned away from software telling him his name is invalid, and the idea that these rules could be in place just to cause people like us this annoyance ticked me off.

zeveb 10y ago

> If someone's valid email address > [*\"32f2@13.31.43.11 > they are up to no good Well, that one in particular, perhaps — but what about "sam & jill"@ourfamily.invalid? What about john(for sly010)@nowhere.invalid? > Also, according to the standard email addresses supposed to be case sensitive, since the username part refers to a unix user and unix is case sensitive. The local-part doesn't refer to a 'Unix user'; it is what it says on the tin: the local part. It's up to the receiving server to determine what it wants to do with case. It's the duty of other servers to preserve the email address as transmitted. > I work with a lot of email address lists originally collected on paper and of course noone knows that. So as bad as it sounds, part of my sanitation process is to lowercase everything. I might use the email address as given, and if that bounces try lowercasing. I don't know of anywhere that has case-sensitive names, but it's conceivable.

sly010 10y ago
I am all for doing things by standards, but to me this is de facto. No one uses case sensitive emails. If they did all sorts of weird things would happen: People couldn't log in, but other people could. There would be multiple accounts when there should be only one, etc. You would have to store every email in original format and in some canonical format for uniqueness, etc. It's a nightmare. If I had to guess the main reason this apocalypse is not happening already is because by default mysql indexes are case insensitive, so dude@dude.com is the same as dude@DUDE.com, so people who use mysql never realize this being an issue.