Ever since its inception, membermeister made email communication an essential part of its feature set and I would like to take this opportunity to explain what we do to ensure the email messages you send via membermeister reliably reach their recipients. We appreciate how important consistent message delivery is for our customers and we are committed to ensuring your messages get to their recipients.
We have chosen a well established and experienced third party provider to handle the sending of email messages for us. We use mandrill, a specialised email service provider which is part of mailchimp who in turn are arguably the world's most well known email marketing platform. Mandrill has been extremely reliable for us over the years.
Every mandrill customer builds up a so called sender reputation and many factors play into achieving a good reputation level. Things such as message content, the number of bounced messages, the presence (or rather lack of a presence) of the sender in many of the publicly maintained blacklists as well as spam complaints make up the sender reputation. Many other factors play a role in ensuring that emails get successfully delivered and some of those factors are quite technical. Nevertheless I will try and cover most of them in this article.
At membermeister we have achieved the best possible sender reputation which mandrill classes as 'Excellent' so we were very disappointed when a few customers reported that some of the messages sent via membermeister had landed in their own customers' spam folders. This was highly unusual - reports of this kind are rare.
Some background, our typical deliverability rate is 99.7 - 99.8% with a message volume of around 10,000 to 15,000 messages per day. The 0.2% of messages that don't make it are primarily made up of hard bounces (an invalid email address), followed by soft bounces (a temporary issue on the recipient's side) and very few spam complaints (this is when someone manually marks a message as spam).
Automatic spam detection
When we investigated the cases of messages that were falsely being flagged as spam we noticed that mandrill (and any other email provider for that matter) only gets notified of a spam complaint when the recipient manually marks the message as spam. This means that an automatic spam filter will not show up in the reports as a spam message, meaning a message that appears to be successfully delivered (the postman has put it through the door) may still end up in spam (get eaten by the dog) before the recipient has seen it.
Why a particular message ends up in spam is almost impossible to establish (short of the message itself coming from a Nigerian prince that wants to transfer $3 million to your account). But through our long experience with software we had a rough idea where to look.
Shared IP addresses
When a message is sent out by a provider they usually use a range (or pool of) IP addresses to do so. Think of an IP address acting like a postcode - you can use the IP to see what neighbourhood the message came from, in this case it shows up as mandrill as they own the sending IPs.
A provider such as mandrill will rotate the IP addresses they use for sending constantly in order to maintain a good reputation for each IP address. Being part of their customer pool, membermeister also gets assigned new IP addresses pretty much all the time.
What we think may have happened (we cannot be sure) is that another mandrill customer (let's call them the noisy neighbour) has sent some rogue emails and this has resulted in one of the IP addresses to drop in reputation and given the neighbourhood's postcode a bad name. While this is not permanent, it can affect message delivery for a while until the reputation is built back up.
It is possible that some messages from membermeister have as a result of this noisy neighbour been classed as spam even though they clearly were not. In other words, the receiving email providers such as Gmail, Hotmail, Yahoo etc. do not 'trust' the message quite as much if it comes from a bad postcode. No matter what you write, the marker that the IP reputation leaves is too great to get that message into the inbox and it ends up in spam instead.
While we cannot be sure that messages being incorrectly classed as spam was an issue in our case, we have taken steps to mitigate this issue from occurring again for this reason. In the future we will be sending via our own, dedicated IP address.
We are currently in the process of 'warming up' our own IP address. This involves gradually increasing the volume of messages that membermeister sends via this single, dedicated IP address.
As it stands, we have so far sent 16,271 messages via the new IP address and the delivery rate is currently at 99.9%. We expect this to level out in line with the usual 99.7%-99.8% that we are seeing but the key difference is that our dedicated IP will eliminate the possibility of our reputation getting 'populated' by a noisy neighbour.
We are carefully monitoring the reputation of this new IP address and have so far achieved a score of 100/100. Our aim is to keep it as close to 100 as possible.
Testing for spam content
We have also set up a dedicated Gmail account that we use to test a wide selection of messages on using the shared IP pool to send from. The results were very encouraging:
Out of over 15,000 messages not a single message landed in spam.
While this doesn't mean that all customers will achieve similar results, it does show that there is no system-wide issue affecting all messages from membermeister.
In addition to the above we have also started collecting and analysing our DMARC data. DMARC stands for Domain-based Message Authentication, Reporting & Conformance and it is essentially a way to make it harder for rogue senders to spoof the sender of an email message. In other words, with DMARC in place it is almost impossible for someone else to pretend to be membermeister, send rogue messages and affect our reputation.
It also sends a signal to the receiving provider that the sender is 'legit' and takes their email delivery seriously. It essentially verifies us as the owner of the sending domain which again adds to the sender reputation.
Automated spam tests
Using another third party service we now monitor specific email messages for their spam content. These tests will tell us if a particular provider suddenly has a problem with a message that usually went through fine, for example an invoice message. So far this test has not thrown up anything of concern but we will continue to run it daily.
Whilst mandrill gives us some information on bounced emails and our overall bounce rate is very low we still have decided to put some more granular logging and analysis in place. With the new monitoring system we can dig down deeper into the specific reasons a particular message has bounced and we can feed this information back to you, our customer, if needed.
We're particularly interested in catching any manually flagged spam messages and we are considering implementing a system that informs you about a particular customer of yours that has flagged a message as spam. After all, they are your customers and should expect emails from you. In many cases we suspect that this happened by accident as in Gmail for example, the buttons for delete and spam sit right next to each other.
A job like this one is never done - technology changes constantly and new features are added and removed from email systems all the time. We are committed to ensuring a safe delivery of your messages and we will continue to invest both money and manpower in this on your behalf.
Some features we are considering for the future include:
- Removal of PDF invoices, replacing them with an online invoice instead. This will have a marginal benefit as some providers, especially people's work email that is provided by their employer, do not like attachments.
- Better exposure of any bounce reasons directly to you, the customer.
- Creating individual accounts for every membermeister within mandrill - that way we can spot if a particular membermeister customer is causing our overall sender reputation to drop. Added benefit: the reputation of one account won't affect another and we can, if needed, implement the necessary logic to send messages from a questionable membermeister account (we've not had one yet!) via a different IP or shared IP pool instead.
I hope this has given you a bit of an overview of how we handle things behind the scenes for you and if you have read all the way to here: well done you! 🎉
As you can see, we do a lot more than simply hitting send :-)
In case you aren't a membermeister customer yet, do reach out for a free trial.
PS: we promised a behind the scenes look so let's go live to membermeister HQ where Paul is busy troubleshooting your emails...