Hello,

Your mail server needs to add a DKIM header to each outgoing mails.

From my undertsanding, you are running CentOS and I guess Postfix. So, this page might help you set this up : [tecadmin.net...]

I assume from the above that SPF is ok.

I run a postfix server with dkim and dmarc milters, which deal with the signing and detection. I have appropriate DNS entries. You need to set up a TXT record for each DNS entry (unless your hosting company uses RREC records). You also need a valid SSL Certificate - letsencrypt is easy to set up but it must be for the mail domain including host (eg mail.example.com)

My setup is typically (note essential quotes!):

SPF:
HOST: (none)
VALUE: "v=spf1 mx -all"

DKIM:
HOST: mail._domainkey
VALUE: "v=DKIM1; h=sha256; k=rsa; s=email; p=(key)

ADSP (not absolutely needed):
HOST: _adsp._domainkey
VALUE: "dkim=all"

DMARC:
HOST: _dmarc
VALUE: "v=DMARC1; p=reject; pct=100; rua=mailto:dmarc-rua@example.com"

You may have variations on this, of course.

For testing I use (among others - note these were valid in 2017):
[dmarcian.com...]
[sparkpost.com...]
(actually a mail-marketing tester)
[checktls.com...]

> I'm checking out my email deliverability with mail-tester.com, and I'm having 2 errors that confuse me

So you are not having actual email sending problems where you are seeing these issues - only when you test your server against the various online services?

Yes and no. I've had an issue for awhile where emails I send end up in the recipients spam folder. I've NEVER spammed, but when someone emails me about an ad or something and I reply, they practically never get it. So that's the problem I'm really trying to fix.

Which led me to mail-tester.com's results.

Spam folder - depends on the service. On some large mail services one sent-to-spam operation will prejudice future mail from the same source. Used to be that original spam could have been consigned to the spam folder by ANY customer, but I don't know if that's still a scenario.

When you say they never get it - are you sure that's the case or do they just not bother to reply?

Have you checked your IP and mail server url in blacklists? There are a few multiple lists around to save you checking individual ones.

When you say they never get it - are you sure that's the case or do they just not bother to reply?

I mean, I can't be 100% positive with everybody... but there have been DOZENS of times that someone emailed me about an ad and I replied, then a week or two later I get another email complaining that no one replied. Or I see them in person and they say they never got it.

Just last month I lost $600 from someone that was wanting to advertise 4 events. They got my emails with rates and everything, but when I sent proofs they just never got it. They ran billboards and newspaper ads so I don't think it was an issue of not wanting to promote it, and they seemed excited about it while we were talking rates. I can't be positive, but I feel pretty confident that my email either went to their spam folder, or it just never showed up at all.

Have you checked your IP and mail server url in blacklists? There are a few multiple lists around to save you checking individual ones.

I use mxtoolbox.com to keep an eye on things like that, and so far we're not on any lists. My old VPSs IP did show up a few years ago when one of my hosting clients had a virus and was inadvertently sending out a ton of spam before I caught it, but that was... 3 years ago, maybe?

> but when someone emails me about an ad or something and I reply, they practically never get it.

Something even the bloated companies like gmail have yet to figure out is that when a user sends an email to you, with a certain subject, and you reply, gmail can't figure out that since your email and subject line matches what their user sent out hence it probably can't be spam. And even though their bots are constantly reading your mail they can't figure out a legit reply from an OTB spam. Don't knock yourself out trying to fix that - it's got nothing to do with your out-bound mail server.

I wish I could, but my Adsense RPM is roughly 1/5th what it was a few years ago so I have to focus on direct sales. But I can't rely on them to get my emails, and I don't have the resources to do phone-sales or to drop in unexpectedly to talk about it (which isn't the most professional technique, anyway).

It's like, I keep hitting road blocks every direction I go >:-(