There was another thread on mailop today about email filtering. This one was about Microsoft and SmartScreen. After watching a bunch of folks make lots of comments about what SmartScreen was, and get it wrong, I waded in. One thing that I always thought was common knowledge, but apparently isn’t, is that SmartScreen is primarily a content filter. Microsoft does use IP and domain reputation...
Details matter
I field a lot of delivery questions on various online fora. Often people try and anonymise what they’re asking about by abstracting out the question. The problem is that there are very few answers we can give in the abstract. What are some examples of these types of questions? Should you always remove an address that hard bounces? Well, in general, yes. But there are a small number of cases...
Microsoft and SPF
Many deliverability folks stopped recommending publishing SPF records for the 5322.from address to get delivery to Microsoft. I even remember Microsoft saying they were stopping doing SenderID style checking. A discussion on the emailgeeks slack channel has me rethinking that. It started out with one participant asking if other folks were seeing delivery improvement at MS if they added a SPF...
Why is DMARC failing?
Multiple times over the last few weeks folks have posted a screenshot of Google Postmaster tools showing some percentage of mail failing DMARC. They then ask why DMARC is failing. Thanks to how DMARC was designed, they don’t need to ask anyone this, they have all the data they need to work this out themselves. The DMARC protocol contains a way to request reports when DMARC authentication...
New Deliverability Resource
The nice folks over at Postmark shared a new deliverability resource last week. The SMTP Field Manual. This is a collection of SMTP responses they’ve seen in the wild. This is a useful resource. They’re also collecting responses from other senders, meaning we can crowdsource a useful resource for email deliverability folks.
False 550 responses from Verizon
This week there was a reported uptick in user unknown responses for verizon email addresses. The specific response folks were seeing was: 554 delivery error: dd xx@verizon.net is no longer valid. [-20] -mta4047.aol.mail.bf1.yahoo.com This appears to be a problem with their require-recipient-valid-since header checking. They are aware and are working on a fix. What this means for senders is if...
Conferences and Pac Man
On the emailgeeks slack channel someone asked for advice about going to conferences. There were lots of great suggestions. I threw in the Pac Man Rule and realised a lot of folks haven’t heard of it before. Eric Holscher created the Pac Man rule. The rule is really simple. If you’re standing in a group talking at a conference a circle can make it challenging for new people to join you...
Spam is never timely nor relevant
One of the ongoing recommendations to improve deliverability is to send email that is timely and relevant to the recipient. The idea being that if you send mail a recipient wants, they’re more likely to interact with it in a way that signals to the mailbox provider that the message is wanted. The baseline for that, at least whenever I’ve talked about timely and relevant, is that the...
Should you publish a DMARC policy statement?
DMARC is a protocol that makes it very, very simple to shoot yourself in the foot. Setup is tricky and if you don’t get it exactly right you risk creating deliverability problems. The vast majority of companies SHOULD NOT publish a DMARC policy with p=reject or p=quarantine for their existing domains. DMARC policy statements are, essentially, a way for a company to assert the following...
Spamming for deliverability
This morning I woke up to a job offer. I hear a number of other email deliverability folks received the same job offer. I am writing to you from [Company]. We are one of the oldest and best reputed partners for Salesforce. We have succeeded because we only hire the best, most experienced developers. We have a need for an excellent expert in deliverability. We have been...