Scott - I'm out of hair to pull out over this email BS (bad stuff), I've done everything in the link you suggested, and FAR, FAR more*, so I'm willing to just do whatever is necessary, or else I basically need to abandon the whole project! I've jumped through every possible hoop to no avail! My webhost recommends Google's email svcs ($5/month/user/email) as their 'weight' along with their high authentication processing means few inbound email servers will block them or even mark them as spam. Q2A's email seems excellent to me in the 'email department', so I'm tempted to go with Mailgun, since I see they offer 10k emails per month for free! I will certainly be below that threshold, AT LEAST in the beginning! That seems like a wiser choice to me. would you say they are reliable and you have no real problems? IOW, once it's set up you need not do anything but check it occasionally (and pay if you're >10k users, of course!), I hope! And, why are they offering the free svc for <10k emails? I trust they are not a not-for-profit company, LOL, - and the word "free" obviously throws up all sorts of red flags in my mind! I realize you're not speaking for them, but I'm simply asking you as a customer of theirs...
* - several days of repeated tech support human-voice-to-human-voice, high-level (not just techs, but usually senior level administrators) of competent tech support as possible with every major email ISP (AOL, HOTMAIL, GMAIL, YAHOO, etc.) Jumping through every authentication or other hoop and requesting every change that they desire, and marking every email that was occasionally accepted as "NOT SPAM" from my spam/junk folders. And all of my p/w's are changed and highly-secure, in case it was malware that was using my PREVIOUS IP as a free-for-all apparently, and yes I did deep scans, to no avail on every computer I use to access my webhost's account! I changed the PTR to better point to the the webhost, MY_USERNAME'S-SERVER.MYWEBHOST.COM, which "dig -x " resolves to from the email recipients IP addy, reportedly via the view source style coding. Also having someone more knowledgeable than I try changing my MX, A, and TXT, etc DNS records, still my (as is seemingly unavoidable) RECYCLED new IP addy for my outbound email is not black/gray-listed, but I ALSO can't get it white-listed, and it reports back as having a "BAD"-reputation, the worst possible mark tagged by most ISPs! AHHHHHHHHHHHHHHHHHHH! I've tried every form of authentication recommended by all common ISP's that deal w/email, and nothing gets me from being BLOCKED, set aside tagged as spam (very rarely am I so Lucky) which literally wets my pants! If someone would somehow set up a more universal email standard (understandably hard, considering spammers), they would be the next frickin' Bill Gates/Steve Jobs, no?! I never "give-up" on any problem, but I'm considering the price of my time at this point and weighing them against the chaos of email in this case! I've not slept in almost 3-days now, so I apologize for my tone! This is quite a serious problem for a realistic site to maintain realistic-ness, the ability to get a single freaking email across to someone that wants it to be accepted (but may not know how to set rules/filter/adjust spam setting! I realize it's not this OS s/w's problem really! I concur! But it's admittedly enough to drive otherwise serious contributors away in some cases (who knows how many?!) Like I am always bent on seeing something through,but I don't believe that everyone shares my attitude! (again, not a negative comment being stated here, just universally)!