Wietse wrote: > In that case, arrange for whitelisting like ever legitimate sender does.
I do that for Gmail, Yahoo, Microsoft, AOL .. and it works, so much so that we have never been graylisted by any of those folks despite the tens of thousands emails we send daily. But I can't afford do that for the thousands of other ESPs that my clients use. We actually stop emailing users after the second failure and let them know about it upon login to the web dashboard. Users normally contact their ESPs on their own and once sorted they normally ask us to restore their alerts. And sometimes they just create a new email account in a big free ESP .
