Each inbox provider uses a mix of technology to best filter the emails it receives, which means – unfortunately for us – that there is no one-size-fits-all for deliverability.
Therefore, it is important to have at least a passing knowledge of the main differences between email services and where you can find information or support.
Identify the Main Blacklists
When talking about emails, a blacklist lists senders employing techniques that look like spam or – worse still – cybercrime. There are different types of blacklists; some are based on IP addresses; others use domain names.
Though there are hundreds of blacklists online, only a handful impact your everyday deliverability. The most powerful blacklist is Spamhaus. If you get listed on Spamhaus, your emails will likely be blocked by most messaging services in the world.
The main blacklists based on IPs:
Spamhaus: The biggest spam-fighting organization (lots of ISPs and webmail operators use their blacklists). Their interface allows you to check whether your IP or domain names feature on their list.
SpamCop: A free service (provided by Cisco) allows people to report spam (SpamCop will alert the message sender to the spam report). This service has its own network of spamtrap addresses.
SORBS: This blacklist, owned by Proofpoint, lists over 12 million servers known for sending spam.
Barracuda: Barracuda Central is the blacklist managed by Barracuda. It is available free of charge on a self-identification basis.
The main blacklists based on domain names:
SpamHaus: See above.
SURBL: A list of websites that have appeared in messages deemed to be spam. It is not a list of senders.
URIBL: This site lists domain names that have appeared within emails considered spam.
Invaluement: A list of domain names that have appeared within emails deemed to be spam.
Several services let you check whether or not your domain name or IP is on a blacklist, such as the free service offered by Multirbl.
Optimize Deliverability for Different Providers
Here is a general framework for each inbox provider, if the service shares reputation details with email senders, and a few links.
Microsoft
When talking about Microsoft, we’re mainly talking about their public messaging service instead of Microsoft Exchange, which is Microsoft’s corporate messaging service.
Microsoft uses behavioral data, user panels, and universal signals to compile a reputation score mainly based on your reputation at the IP level.
Domains: outlook.com / hotmail.com / live.com / msn.com / etc.
Availability of reputation data: delivery errors / complaint rates / IP reputation / spamtraps
Access to reputation data: https://postmaster.live.com/snds
Resource and support center: https://postmaster.live.com
Support: http://go.microsoft.com/fwlink/?LinkID=614866
Google controls about 43% of the world’s inboxes. As a destination, Google includes both the public Gmail service and Google Workspace for companies. Google has a strong focus on behavioral data when compiling its reputation scores based on your domain and IP address reputation. The email fingerprint is also very important.
Domains: gmail.com / googlemail.com / company domains
Availability of reputation data: complaint rates / delivery errors / level of authentication / encryption rate / domain reputation / IP reputation / use of feedback loop
Access to reputation data: https://postmaster.google.com
Resource and support center: https://support.google.com/mail/answer/81126
Support: https://support.google.com/mail/troubleshooter/2696779
Yahoo!
Yahoo! now encompasses the different companies owned by Verizon Media, such as AOL and Yahoo!. These companies use behavioral data and focus on the quality of links contained within emails.
Domains: yahoo.com / ymail.com / aol.com / etc.
Availability of reputation data: None
Resource and support center: https://help.yahoo.com/kb/postmaster/
Support: https://help.yahoo.com/kb/postmaster/
Let’s Recap!
Each messaging service has a different way of filtering spam.
Blacklists feature dubious operators.
The most powerful blacklist is Spamhaus.
Before We Go
That’s it! You’ve come to the end of the course - congratulations!
So before we say goodbye, let’s end with just a few tips on what makes a great email strategy.
A great email strategy:
Combines marketing/selling emails with editorial/information emails.
Clicks and converts for marketing emails.
Builds a relationship for editorial emails.
Communicates regularly with contacts.
Helps reputation and deliverability - but also helps keep your contacts engaged with you.
Achieves relevance.
Targets an audience that will find them interesting with the help of great segmentation.
Are reviewed regularly. Every month (or at least every quarter), take a step back and review/analyze the effectiveness of your strategy - and don’t be afraid to make changes.
With all this in mind, take a deep breath and tackle your campaigns. You are ready! Good luck and I hope to see you here soon in your next course, here at OpenClassrooms.
