When looking at various tutorials on configuring postfix, it’s quite easy to configure a catch all for a certain domain. So any username at the said domain gets forwarded so a said maibox. However, I haven’t been able to find any article describing to do the reverse, catch a said username on any domain.

The reason for this is to catch abuse@, postmaster@, webmaster@ etc. any domain on my servers. When going through the postfix documentation another time I realised it support regular expressions. Using regular expressions this can be fixed

put a file /etc/postfix/regexp-aliases

^webmaster@/i  destination@email.address
^postmaster@/i destination@email.address
^abuse@/i      destination@email.address

Then open /etc/postfix/main.cf and add

regexp:/etc/postfix/regexp-aliases

to virtual_alias_maps = .

Edit 05-03-2016: added the /i to the example. Email user names are supposed to be case insensitive.