Question

I’m using Postfix MTA and get important mails in from a broken MTA (which I can’t fix because it’s not under my control), which sends in the following format:

RCPT TO: <[phone]>

What I need is:

RCPT TO: 4968112345678

So I am looking for a regex, which first checks if the string begins with “RCPT TO:” and if this is true, it needs to remove all special characters after it, so that only [a-zA-Z0-9] are left.

Postfix ships an example for such regex’es:

# Work around clients that send RCPT TO:<'user@domain'>.
# WARNING: do not lose the parameters that follow the address.
#/^RCPT\s+TO:\s*<'([^[:space:]]+)'>(.*)/     RCPT TO:<$1>$2

But after several hours I am unable to adapt it to my needs.

Thanks in advance,
Marco

Answer 1

It seems to be, that it is not possible to strip any combination of non-alphanumeric characters in generic case. But for addresses like given in example this regexp should be sufficient:

/^[^a-z0-9]*([a-z0-9]+)[^a-z0-9]*([a-z0-9]+)[^a-z0-9]*([a-z0-9]+)$/     $1$2$3

You can test regexp maps via postmap command:

$ postmap -q "[phone]" pcre:/path/to/regexp_map
4968112345678

To use this regexp map add to postfix config

canonical_maps = prce:$config_directory/regexp_map

Read ADDRESS_REWRITING_README about canonical_maps.