All filters are not equal

Many questions about delivery problems often assume that there is one standard email filter and the rules are the same across all of them. Unfortunately, this isn’t really the case.

The biggest divide is consumer versus business filters. Business filters don’t really care about things like engagement. A sender could have near perfect engagement with a message to a business. But a decision maker inside the company can still decide that mail doesn’t get in. There’s no appealing to permission or wanted mail. Employee mail is provided for the good of the business, not for the good of the individual user or the sender.

There are other less obvious divides between filters as well.

I frequently refer to “webmail providers” (Oath, Microsoft, Gmail). These are companies that control the mail delivery and, for the bulk of their customers, control the mail client as well. They can use engagement filters because they have more data. Other companies, like broadband providers or web hosting services, don’t have the same level of access to customer behaviour, so they can’t heavily use engagement as part of their filtering processes. They may have some access to IMAP folders, depending on their setup, so they can look at some engagement flags.

Filtering companies also have their own type of filters. In many cases, though, they have no access to any engagement filters. They handle mail at a discrete point that starts during SMTP sessions and ends when the mail is handed off to the local delivery agent. These companies cannot use engagement as part of their filtering process all, they simply don’t have access to that data.

Understanding what data filters act on and what data they have access to can inform how to deal with blocks and delivery problems.

 

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URL reputation and shorteners

A bit of  a throwback post from Steve a few years ago. The problem has gotten a little better as some shortening companies are actually disabling spammed URLs, and blocking URLs with problematic content. I still don’t recommend using a public URL shortener in email messages, though.
Any time you put a URL in mail you send out, you’re sharing the reputation of everyone who uses URLs with that hostname. So if other people send unwanted email that has the same URL in it that can cause your mail to be blocked or sent to the bulk folder.
That has a bunch of implications. If you run an affiliate programme where your affiliates use your URLs then spam sent by your affiliates can cause your (clean, opt-in, transactional) email to be treated as spam. If you send a newsletter with advertisers URLs in it then bad behaviour by other senders with the same advertisers can cause your email to be spam foldered. And, as we discussed yesterday, if spammers use the same URL shortener you do, that can cause your mail to be marked as spam.
Even if the hostname you use for your URLs is unique to you, if it resolves to the same IP address as a URL that’s being used in spam, that can cause delivery problems for you.
What does this mean when it comes to using URL shorteners (such as bit.ly, tinyurl.com, etc.) in email you send out? That depends on why you’re using those URL shorteners.
The URLs in the text/html parts of my message are big and ugly
Unless the URL you’re using is, itself, part of your brand identity then you really don’t need to make the URL in the HTML part of the message visible at all. Instead of using ‘<a href=”long_ugly_url”> long_ugly_url </a>’ or ‘<a href=”shortened_url”> shortened_url </a>’ use ‘<a href=”long_ugly_url”> friendly phrase </a>’.
(Whatever you do, don’t use ‘<a href=”long_ugly_url”> different_url </a>’, though – that leads to you falling foul of phishing filters).
The URLs in the text/plain parts of my message are big and ugly
The best solution is to fix your web application so that the URLs are smaller and prettier. That will make you seem less dated and clunky both when you send email, and when your users copy and paste links to your site via email or IM or twitter or whatever. “Cool” or “friendly” URLs are great for a lot of reasons, and this is just one. Tim Berners-Lee has some good thoughts on this, and AListApart has two good articles on how to implement them.
If you can’t do that, then using your own, branded URL shortener is the next best thing. Your domain is part of your brand – you don’t want to hide it.
I want to use a catchy URL shortener to enhance my brand
That’s quite a good reason. But if you’re doing that, you’re probably planning to use your own domain for your URL shortener (Google uses goo.gl, Word to the Wise use wttw.me, etc). That will avoid many of the problems with using a generic URL shortener, whether you implement it yourself or use a third party service to run it.
I want to hide the destination URL from recipients and spam filters
Then you’re probably spamming. Stop doing that.
I want to be able to track clicks on the link, using bit.ly’s neat click track reporting
Bit.ly does have pretty slick reporting. But it’s very weak compared to even the most basic clickthrough reporting an ESP offers. An ESP can tell you not just how many clicks you got on a link, but also which recipients clicked and how many clicks there were for all the links in a particular email or email campaign, and how that correlates with “opens” (however you define that).
So bit.ly’s tracking is great if you’re doing ad-hoc posts to twitter, but if you’re sending bulk email you (or your ESP) can do so much better.
I want people to have a short URL to share on twitter
Almost all twitter clients will abbreviate a URL using some URL shortener automatically if it’s long. Unless you’re planning on using your own branded URL shortener, using someone else’s will just hide your brand. It’s all probably going to get rewritten as t.co/UgLy in the tweet itself anyway.
If your ESP offers their own URL shortener, integrating into their reporting system for URLs in email or on twitter that’s great – they’ll be policing users of that just the same as users of their email service, so you’re unlikely to be sharing it with bad spammers for long enough to matter.
All the cool kids are using bit.ly, so I need to to look cool
This one I can’t help with. You’ll need to decide whether bit.ly links really look cool to your recipient demographic (Spoiler: probably not) and, if so, whether it’s worth the delivery problems they risk causing.
And, remember, your domain is part of your brand. If you’re hiding your domain, you’re hiding your branding.
So… I really do need a URL shortener. Now what?
It’s cheap and easy to register a domain for just your own use as a URL shortener. Simply by having your own domain, you avoid most of the problems. You can run a URL shortener yourself – there are a bunch of freely available packages to do it, or it’s only a few hours work for a developer to create from scratch.
Or you can use a third-party provider to run it for you. (Using a third-party provider does mean that you’re sharing the same IP address as other URL shorteners – but everyone you’re sharing with are probably people like you, running a private URL shortener, so the risk is much, much smaller than using a freely available public URL shortener service.)
These are fairly simple fixes for a problem that’s here today, and is going to get worse in the future.

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It depends… no more

The two most hated words in deliverability. Many people ask general questions about deliverability and most experts, including myself, answer, “It depends.”
There are a lot of problems with this answer. The biggest problem is that it’s led to the impression that there are no real answers about deliverability. That because we can’t answer hypothetical questions we are really just making the answers up.
Depositphotos_53649203_original
The reason we use “it depends” is because the minute details matter when it comes to deliverability. Wether or not something will hurt or help deliverability depends on the specific implementation. Who’s doing the sending? What is their authentication setup? What IP are they using? How were the addresses collected? What is their frequency? What MTA is used? Are they linking to outside sites? Are they linking to outside services? Where are images hosted? The relevant questions go on and on and on.
I am going to stop saying it depends when answering generic deliverability questions. Instead I will be using the phrase “details matter.” Details do matter. Details are everything. Details drive deliverability.
Details Matter
The importance of details is why many deliverability people hedge their answers. The details do matter.
I will do my best to stop answering It Depends to deliverability questions. Instead, I’ll be answering with question and pointing out the details matter.
 

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