My guess is that they are trying to prevent a spammer from registering lots of accounts from a single email address. (And yeah I know there is the fee to dissuade that, but who knows what the future may hold...)
They want to spam you later (or sell your address to spammers) and have you not know where they got the address.
> They want to spam you later (or sell your address to spammers) and have you not know where they got the address.
Email +suffixes are easy enough to strip off post-collection if you're aware of them. If they wanted to spam, they wouldn't have to disallow +'s in the validation regex. They must have some other reason for disallowing them, which may be as innocent as poor awareness of them.
Personally, I used Fastmail with my own domain and have abandoned using +suffixes because they're too unreliable. Fastmail has several options for single-use email addresses that should be difficult or impossible for recipients to decode to the main address.
More likely, they just googled "e-mail vaildation regex" and copied the first/smallest result from StackOverflow. Happens all the time.
Re:Micro.blog
by lowercased on Tuesday October 30, 2018 @07:31AM
(#18335503)
not sure that's this. if you just grabbed the first one, you wouldn't necessarily know that it explicitly doesn't work with the "+". Explicitly calling out the "+" issues indicates the person likely knows what they're doing.
Why not? "+" is valid in email addresses.