On Thu, Jan 12, 2023 at 12:46:03PM +1300, DL Neil wrote:
> > That depends on whether you used virtual_alias_maps or alias_maps. Also,
> > there is a limit on the queue file size (with a name message_size_limit
> > that would more accurately be message_plus_envelope_size_limit).
If you're asking the question, perhaps you mean to send mail to lists
of O(10k) or O(100k) recipients. If so, you need to do more than just
expand the alias.
In particular, you'll surely need an "owner-alias", and it would be
best to snapshot the recipient list into a file, which is used via
the ":include:" mechanism of aliases(5). This gets around all limits
other than queue file size for the post-expansion forwarding hop.
You'll probably want to use "VERP" and ensure that the agent that
sends mail to the list uses it.
> Thus, if max-out at a list of ten accounts, and allow for an average
> address 50-characters long, only looking at an (ASCII) total of 500B
> (actual data)!
If you're serious about *10* recipients, then this thread is a waste of
everyone's attention. Nothing interesting happens until you reach at
least ~1000 recipients, at which point you could start hitting at least
the virtual alias expansion or recursion limits.
On the other hand, any time you forward inbound back out to an external
recipient (even just one), you need to worry about SPF, DKIM, DMARC,
your IP reputation and the efficacy of your anti-spam filters, and all
that jazz. The simplest solution is to not redirect inbound mail
outward. Otherwise, you have a bunch of issues of which the recipient
count is the least of your worries.
--
Viktor.
