I see an increase in complaints about emails landing in spam folders. Has delivery quality reduced?

The question is in the title.

As MXroute grows, and considering its focus on providing the best deliverability that it possibly can, the number of complaints about outbound emails landing in spam folders will grow. This is inevitable, and will likely become the most mentioned issue over time. I want to stress that an increase in these topics is an indication of growth and not an indication of decreased sending quality.

You see, avoiding having your email delivered to spam folders remains one of the most difficult tasks of all. To make matters worse, you can only speculate on the reason your email didn’t reach the inbox at most email providers. With that in mind, I want to lay out the layers of responsibility for clarity. There are three layers to deliverability in our view:

  1. IP reputation
  2. DNS settings
  3. Domain / content reputation

We consider ourselves responsible for #1 in almost every case. This means preventing spam, keeping us off of relevant RBLs (blacklists), retrying emails that fail delivery (from different IPs), and working with ISPs to ensure that we meet all reasonable/possible requirements to prevent them from blocking our IP space. This does not mean that we consider it our responsibility if a random recipient has specifically blocked you by blocking our IP, especially where the recipient isn’t someone that anyone else is sending email to (ex. your customer runs their own mail server and they blocked us to halt your emails). We might attempt negotiation in such a case, but that should help understand where we draw the lines in regards to IP reputation.

We consider #2 and #3 to be your responsibility. We enforce #2 to a degree (our policy requires a valid SPF record for senders), and we’re happy to advise to the best of our ability on #3.

Our hope is that you’ll use mail-tester.com and try to get a score of 10/10 to ensure the highest quality delivery that we can offer. If your email still lands in spam folders after that, the speculation about cause starts to get more theoretical. We can’t know, so we’ll propose:

  1. Domain reputation. Entirely possible that your domain is viewed poorly based on a keyword in the domain name, a history of recipients reporting email from your domain as spam, your domain being too young to have built up a positive reputation (we’ve heard relevant in some cases), or even just your domain’s connection to content that has been filtered by a spam filter a number of times and became “spam-like” by correlation.

  2. Content. If you’re struggling to hit inboxes, you might try reducing or removing HTML, images, etc. IP addresses, phone numbers, links, who knows. We’re just trying to offer advice on how to potentially offset the spam score, any of those things “could” play a role in dragging down the spam score.

Then there’s always a third case that people sometimes suspect, and frankly we can’t tell you that it isn’t true, there’s just nothing we can do about it if it is (because no one will admit to filtering this way, much less give us the chance to influence it):

  1. IP reputation + domain + content. It is entirely possible, even if not probable, that IP reputation is one piece of a spam score that is not enough to instantly filter an email to the spam folder, but that it could be a combination of your domain name and/or content with an unpublished bias against an IP address. This “might” explain why one customer consistently hits the spam folder but only when using our IP space, while another customer using our IP space never hits the spam folder.

The third one there is purely theoretical. We’re not saying it doesn’t happen, but we’re not saying it does either. We have no evidence to support the idea that it occurs, it’s just a wild technical theory. All we can do for IP reputation is keep our IPs clean, and that’s something we work our tails off to do.

How can we get 10/10 in mail-tester if we are encouraged not to setup DKIM records?

Could IP reputation be behind this bounce I received today? (My server is friday.mxroute). No mention of domain, and the content was ok (except I was ironically explaining to the recipient how emails end up in the spam folder).

Delivery to the following recipient failed permanently:

Technical details of permanent failure:

554 resimta-po-29v.sys.comcast.net resimta-po-29v.sys.comcast.net found on one or more DNSBLs, see http://postmaster.comcast.net/smtp-error-codes.php#BL000010

whois of the IP…
MXroute MXROUTE-IPV4-1 (NET-172-82-139-0-1) -

That recommendation applies only to the cPanel servers really. And that is because most people cannot follow directions. You may also notice that it is not ‘encouraged’ in this topic.

With the deployment of all new customers on the DirectAdmin based system I’m now satisfied with the workflows that the minor gain is justifiable with the required workflow, but I’m still not convinced that it is worth this gain on average for cPanel users as the workflow is quite bad and the gain typically not enough to offset it.

It would be. Thanks for letting me know. I’ll add mitigation for this bounce error so that you won’t see it again. Please let me know if you do happen to run into it again.