On Mon, Apr 6, 2020 at 12:18 PM Ian Zimmerman <i...@very.loosely.org> wrote: > > On 2020-04-06 14:24, Ashley Dixon wrote: > > > Cheers for the help ! To be honest, I don't think I'd want to receive > > e-mail from someone who cannot resist pressing a button :) > > In fact, "MTAs" that don't retry turn out to be spam robots on close > inspection, more often than not. That is the basis for the spam > fighting tactic called "greylisting". So you will not even be original > in ignoring them. >
More often than not, yes. The main exception I've seen are sites that email you verification codes, such as some sorts of "two-factor" implementations (whether these are really two-factor I'll set aside for now). Many of these services will retry, but some just give up after one attempt. Solutions like postgrey make it easy to whitelist particular MTAs or destination addresses to avoid this problem. I won't say that greylisting has solved all my spam problems but it definitely cuts down on it. Also, by delaying never-before-seen MTAs it also makes it more likely that RBLs and such will be updated before the email makes it past greylisting, which will cut down on "zero day" spam. -- Rich
