Hi!
On 2020-10-14 3:33 p.m., Phil Stracchino wrote:
On 10/14/20 3:20 PM, Nick wrote:
I also have to tell the developers of our applications what should be
allowed...
Good luck with that one. I have encountered INNUMERABLE werb sites
which fervently insist that '+' is not a legal character in an email
address.
Well since we are talking of my employer's own developers for their own
application that will not be much of a problem...
We (I am also one of their developers) will have to allow it...
Is it possible to have more than one "+" sign in the email address, what
does Postfix do when it sees that, does it stop at the first one and
considers everything that follow a sub-addres?
My best understanding is that under RFC2822 and others, '+' is
explicitly a legal character in the local part of an email address, and
there is no stipulation as to how many times it may occur in the local
part. However, it is entirely up to the receiving server how to
interpret single or multiple + characters, and I do not know what
happens if you try to use an address with apparently multiple
sub-address parts because I've never tried it.
What I would ASSUME and EXPECT is that Postfix will treat everything
after the FIRST + as a sub-address and deliver mail addressed to
user+foo+...@example.com to u...@example.com.
That's essentially what I thought too... The first "+" separates the
user part from the extension/sub-address and any additional "+" are part
of the extension/subaddress..
Looks like the relevant RFCs (apart from RFC822, RFC2822 and the ones
that followed) seem to be RFC3598 which was later obsoleted by RFC5233
and none of them seem to say what should happen if the delimiter is
there multiple times...
Funny thing is, they don't actually specify what the delimiter should be
as far as I can tell, that's certainly not the best way of making sure
it will be standardized...
Thank you and have a nice day!
Nick
