How to Find and Fix Email Deliverability Issues.

Email deliverability is the important task for Email administrators and server admins.
Sometimes it is quite difficult to figure out why your email was filtered out or blocked. While some spam filters like SpamAssassin or Barracuda will show the reasons, many others (for example, Google Postini) won’t give you any clue at all. Email headers are not always informative either.

So, how do you find out why a mailbox provider moved your email to the spam folder?

Why our emails are sometimes blocked by mailbox providers ? What is the exact reason behind this ? Here is the 4 solutions to reduce your email goes out of spam folder.

Deliverability issues generally happen if there is something wrong with any or all of the following elements:

• Email content we using for sending.
• May be it's lack of server configuration
• Email address and domain reputation
• IP address reputation

1. Email content

 Email content includes the HTML code, plain text part, and subject line. While contents   has declined in importance in recent years,it still can sometimes cause deliverability issues.

Nowadays, content-based deliverability problems are not limited to a keyword here or there. Spam filters now look at any and all URLs in the message, patterns of content (whether or not it looks like other content that’s been flagged as spam, whether it’s yours or not), HTML code, plain-text version (whether or not it exists), image vs. text ratio, etc.

This may seem like a broad category, but checking your email content as a start is fairly straightforward.It is much more under your control than the reputation of your IP address.

Testing email content

• Start testing by changing the subject line. Remove any words and/or special symbols that might seem  spammy and resend the email.

           There are 7 types of subject lines:

                                 1. How to

                                 2. Question

                                 3. Urgent ( Limited time offer, Last chance)

                                 4. Beneficial

                                 5. Personalised 

• If it doesn’t help, re-write the content avoiding questionable elements. Test it.
• If the issue is still there, remove URLs and test.
• If the email is still filtered, remove images and test again. 
• No luck? Test a plain text message.
• If it does not help, change the template.

               

Correcting Email Content Problems

Check the Spam Assassin report,or test to mailtester.com check the content for the following top problems:

• ALL CAPS in the subject
• Bad HTML (run it through a validator and make sure you don’t have any empty or unclosed tags) 
• Missing plain text part (if you send an HTML message, the text part must be included as well).
• High image rate vs low text rate (spam filters don’t like image-only emails)
• Links and images hosted on crappy and fishy sites (such sites are often blacklisted)
• IP address links (should be avoided in favour of regular URLs)
• Links created by link shortners (can be caught by spam filters)
• Missing unsubscribe link (a must-have for legitimate emails)

2. Server Configuration

      The misconfiguration of the mail server, in particular, missing authentication records like SPF and DKIM,can also cause problems with deliverability.

Note! You could have server configuration issues if you’re managing your own mail server. If you’re with an email service provider, their mail servers are generally set up correctly.

Testing Server Configuration

Send a test through the mail server that you’re using to send your marketing emails so that you get results directly from that server. Please check your authentication result are passed or not by sending a mail to your own email id. Authentication result should be SPF,DKIM,DMARC = PASS. 

Correcting Mail Server Configuration Problems

   If your emails are failing SPF, make sure that the SPF entry in your DNS server matches your sending IP. 

A failed DKIM test is another reason for email filtering and must be corrected, too. DKIM requires the sending server to sign the email using a private key, while the receiving server can look up the public key which is stored on that domain’s DNS server.

If no email at all is being sent from your mail server, it could also be a configuration issue.

3. Email address and Domain reputation

         

          Spam filters create lists of suspicious email addresses and domains based on emails they have previously filtered. If you or other people using the same email or domain were previously sending spam, your emails could be seen as more suspicious by spam filters.

While some mailbox providers look at the IP reputation, more and more mailbox providers are switching to the domain reputation.

For example, Gmail relies on the sender’s domain reputation. If you’re sending a lot of emails to invalid email addresses or receiving a lot of complaints, then Gmail will block your domain.

Testing the Sender Email Address and Domain

If the same email (from the same IP and domain) is delivered to more Inboxes with a different sender email address, the problem could be in your old email address.

If you don’t see a difference in the Inbox placement rate, make a test using an email address from a different domain.

Correcting Sender Email Address and Domain Problems

If you find out that your emails are being filtered due to your sender email address, you should consider changing it. Take this decision wisely, as you should try not to change your sender address too often. 

A consistent sending from the same email address builds trust with your recipients, increases engagement, which will help your deliverability rate!

If the test points to the domain-based deliverability problems, you’ll have to consider setting up a new domain and build a new reputation for it to get your emails delivered.

It is costly and time-consuming considered all the data that needs to be set up on the new domain, but possible if there is no other solution.

4. IP address Reputation 

             

If the IP address that you’re sending emails from has been associated with spam in some way, it may be on blacklists.

For example, AOL has its own IP reputation monitor and rates the sender’s IP reputation as “bad”, “neutral”,and “good”. If your IP reputation is “bad” with AOL, you’ll see your emails filtered out as junk mail or blocked altogether. A “neutral” reputation is generally OK.

Before checking the content of the email, the filters check the IP address to see if it is white- or blacklisted. If it is whitelisted, your email will be delivered without its content being checked at all.

If the IP has been blacklisted, the email will be “black holed,” bounced back or flagged as spam without the content being checked.

Black holed emails are not delivered to the user but are saved in a place accessible to administrators in case they are needed later. This approach is often used for emails that contain viruses, to keep end users from opening them on accident.

Testing the IP Address Reputation

•  To test the IP address reputation, send your email through a different mail server or email service provider. For example, if you’re regularly sending the emails through your own mail server, consider sending it through an email service provider or delivery service such as Amazon SES, SparkPost, Mailgun or other.
• Make sure to keep the same subject, sending address and content.
• If the email was blocked when sent through your server but it is delivered with no problems through an ESP or   delivery service, you may have the IP reputation problem.

Then test your IP against blacklists with the senderscore.org IP Reputation Monitor. You can setup an automated process of checking your IP against blacklists and be alerted via email when the IP got listed. For gmail user goto postmaster.google.com. 

If the email still isn’t delivered when using a different server or email service provider, you may have a problem with one of the things listed above like sender email address/domain reputation or content.

Correcting IP Address Reputation Problems

If a blacklisting issue is observed, go through the removal process. The removal instructions are usually stated on the blacklist’s website.

If de-listing is not possible or your IP reputation is totally killed, you’ll need to acquire a new IP to send from. But it may not solve all of your deliverability issues because spam filters can associate your reputation with your IP address, or domain, or both.

Thus, changing both the IP address (probably by changing ESPs) and the domain would be the best solution, but it is not possible for most companies, as the domain cannot be abandoned.

In this case, change the IP, register a new domain using your brand, for example,brandmail.com, set up a new sending address, and begin using best practices to achieve good engagement and reputation.

A good scenario of the new IP/sending domain warm up is:

                Day 1 – 1000 relays per day and 100 per hour

                Day 2 – 2500 relays per day and 200 per hour
                Day 3 – 3500 relays per day and 300 per hour
                Day 4 – 4500 relays per day and no hourly limit
                Day 5 – 7500 relays per day and no hourly limit
                Day 6 – 9000 relays per day and no hourly limit
                Day 7+ – no limits.

The Bottom Line

 A lot of deliverability problems come from things that many people don’t even think of. You can spend a lot of time and efforts for correcting things we’ve just talked about, but it will work only as a temporary measure if the root of your deliverability problems is your mailing list.

So, before you think about changing the IP or sending address, ask yourself how you’ve got your list. Are those people are that you will be sending emails to them?

Purchasing, renting or harvesting email addresses is the first step to deliverability problems. If you know or suspect that your list contains purchased or harvested addresses, it’s better to throw it away and start collecting emails using a confirmed opt-in method.

Email address collection is the key to high deliverability, but many companies and marketers just don’t care about how they’re collecting email leads and entering into the relationship with them. It can be OK for the time the list is small. But as far as the list grows in size, it comes under a closer examination at the mailbox providers and what used to work before doesn’t anymore.

With that said, the first step to finding the cause of any delivery problem is to look at the list. If your email collection methods are not good, changing email templates, content, IPs or domains doesn’t change the reason email are being filtered out.

So, want good deliverability? Look at how you’re collecting email addresses.

Want to fix deliverability problems? Check how you’ve collected email addresses and how you’re managing them.

(source: glocksoft.com )