In this article, you'll learn many of the actions you can take when troubleshooting the deliverability of your mailings, including:
General Whitelisting Instructions For Subscribers
Asking subscribers to whitelist your "from" address has a positive impact on inbox placement. Below are the two main opportunities subscribers have to whitelist:
- During the "sign-up" process. To avoid mail from being classified as spam (which leads to subscribers missing out on messages), ask your subscribers to whitelist your "from" address prior to receiving their first message from you.
- While they are subscribers. Whether the subscribers' preferences have changed, they forgot to add your address during the "sign-up" process, or your "from" address has changed, you may want to consider adding a preheader to your messages to remind subscribers to whitelist. For example, your preheader could read "Please add '[Email Address]' to your Safe Sender list to ensure uninterrupted delivery. See Preheaders to learn more.
Below are some basic instructions you can provide to your subscribers (or private domain administrators) to whitelist your "from" address.
NOTE: We recommend creating your own Landing Page that contains the instructions below so that your subscribers can access them right away. See the Landing Pages & Forms section and its associated articles to learn more.
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Below are instructions for common spam filters.
- Trend Micro - Click HERE for instructions
- Cloudmark - Click HERE for instructions
- Mimecast - Click HERE for instructions
- Symantec - Click HERE for instructions
- Log into the Exchange Admin Center.
- Navigate to Protection.
- Select Spam Filter and click the Pencil icon to edit.
- Select Allow Lists. Add the following domains: (1) The domain used as the "from" address, and (2) Informz.net.
Below are instructions for common email clients.
- Right-click a message in the preview pane (double-check the Junk and Clutter folders for messages too).
- Click the drop-down list and select Junk.
- Select Never Block Sender's Domain.
NOTE: If the message was found in the Junk or Clutter folder, you can move it to the inbox.
- Click the Gmail drop-down list (on the left side of the screen) and select Contacts.
- Add the "from" address to your contact list.
If the message was found in the spam folder, right-click it and select Not Spam. Additionally, you can move messages to their proper classification folder if needed.
Right-click on a message and select Add to Contacts. Alternatively, select Contacts on the left sidebar and add the sender's "from" address. If the message was found in the spam folder, right-click it and select Not Spam.
- Click the Contacts icon (in the upper left corner) and select New Contact.
- Add the sender's email address.
If the message was found in the spam folder, right-click it and select Not Spam. if you see the address in the block list, select the address you wish to remove and click Remove.
Other Email Clients
Add the sender’s “from” address to your contact list/address book. If the message was found in the spam folder, move it to the inbox or right-click it and select Not Spam.
Deliverability Issues - Bounced Messages
If you are maintaining a good sender reputation, following list best practices, and using a dedicated sending IP, you are less likely to experience deliverability issues. However, you may come across some bounces and blocks, so ruling out major pitfalls may help get to a solution.
With that said, it is important to remember that mail receivers and spam filters are protecting their users from spam and do not fully disclose their filtering rules (each system has a different set of rules), so sometimes it can be difficult to get to a specific resolution.
To assist you in troubleshooting a deliverability issue, you can follow the steps below to rule out some of the major causes:
Step 1 - Check DKIM authentication on sending domain(s)
Use one of the two methods below:
- Navigate to Admin > Setup > Email Authentication and follow the steps in the Email Authentication section of the Sender Authentication page to test.
- Using this template, create an email address based on an email account you currently own. For example, to send the results to: email@example.com the sample message should be sent to "firstname.lastname@example.org" You would then create a mailing in Marketing Automation Professional (MA Professional) (or use an existing one) and publish the email to your unique address that you created. You will receive the authentication results to your email account (example below of SPF and DKIM passing)
Summary of Results
- SPF check: pass
- "iprev" check: pass
- DKIM check: pass
- SpamAssassin check: ham (NOTE: this can be ignored for the authentication tests)
If the DKIM check is neutral or failing, then it is highly recommended DKIM authentication is completed before continuing to the next step.
NOTE: Refer to the Email Authentication section of the Sender Authentication page for more information.
Step 2 - Check the setup and content of the mailing
- Make sure the “from” address used for the mailing has been authenticated with DKIM.
- If there was a large spike or dip in volume, some mail receivers will classify the message as spam.
- Check to see if there are any exposed URLs in the body of the mailing (e.g., www.website.com). If so, cover them with text or an image to avoid being misconstrued as a phishing attempt.
- Does the mailing contain any third party or short links? (e.g., bit.ly, sbn29.com, etc) If so, consider using an alternative because short links are typically blacklisted and may cause your emails to be blocked or classified as spam.
- Are any URLs used in your mailing on a known blacklist? Check your URL's reputation.
- If using images in the body of your mailing, make sure you have enough text to go along with it in order to create a good balance. Using only images with no text can look suspicious because spammers have been known to hide text and other malicious content embedded in an image.
Step 3 - Look at the sent mailing results
- Check to see if you received any subscriber complaints or unsubscribers in the Key Metrics tab of the sent mailing (Mailings > View > Sent). This is a key component in determining your sender reputation and how your mail is being classified.
- Look at unsubscribe reasons to help understand some important deliverability questions (do individuals consider your messages spam, are you sending too frequently, are you sending to the wrong audience, etc.).
- Select one of the bounce types in your mailing (soft, hard, or blocked) in order to get to more detailed info.
- Select a recipient from the list and navigate to the Mailings tab. Then, select the Blocked or Bounce link to view the detailed error message.
- Look for the Diagnostic-Code within the blocked or bounce message details. Sometimes, you will be able to see what may have caused the bounce to occur (spam content, ISP or spam filter block, poor sender reputation, blacklisting, etc.).
- You can see if a block is affecting specific domains if you navigate to the Details tab > Non Delivered > Domain Blocks.
- If the block is concerning a small, private domain, we recommend doing this.
- If the block is concerning a major ISP, such as AOL or Comcast, you may want to submit a ticket to request the block be lifted. You can also submit a case to Higher Logic for additional deliverability assistance.
To sum up...
- Only send from domains that are authenticated through MA Professional
- Only send messages to individuals who have affirmatively opted in (our rules of use)
- Keep mailing lists updated and follow best list practices
- Many email providers look at user engagement when classifying mail
- Keep your sending volume consistent
- Check the content and subject line for deliverability best practices (check using MailTester)
- Maintain a good sender reputation
A bounce occurs when a mailing cannot be delivered to a particular email address. There are several bounce classifications: soft bounces, hard bounces, and blocks. Ultimately, if you are experiencing multiple bounces, you may need to clean your subscriber lists and target groups to improve your deliverability.
Let’s take a look at the key reasons you might experience each bounce type.
A soft bounce generally occurs for one of the following reasons:
- The mail server was down
- The mail server was not accepting mail
- The subscriber’s inbox was full
You can generally resend a mailing to subscribers that soft bounced at a different time to ensure that they receive your message. Soft bouncers are automatically re-tried (i.e., re-sent a mailing) at certain intervals based on domain.
A hard bounce generally occurs because:
- The domain does not exist
- The domain does not have a mail server
- The email address does not exist in the domain
These addresses cannot receive a message because there is no place/address to receive the mailing.
A blocked email address is any email address that may remain deliverable, but is rejected by the receiving mail server (for example, an anti-spam filter rejects your mailing).
When a specific email address bounces multiple times, email addresses become known as repeat bouncers. These can be determined by soft, hard bounces, and blocked (see rules below). Repeat bouncers are automatically unsubscribed.
Because bouncing can cause deliverability problems, MA Professional uses the following rules to evaluate bounce status and suppress the email address when it reaches the repeat bouncer status. Note that these rules draw on data from the past 90 days of mailing activity.
- After three consecutive hard bounces, a subscriber’s delivery format is automatically switched to Text.
- After four consecutive hard bounces, a subscriber becomes a repeat bouncer.
- After six consecutive bounces (a combination of soft, hard, or blocked), a subscriber’s delivery format is automatically switched to Text.
- After seven consecutive bounces (a combination of soft, hard, or blocked), a subscriber becomes a repeat bouncer.
- After one hard bounce, an AOL email address becomes a repeat bouncer.
- Admin, Login, and Test email addresses do not become repeat bouncers.
What to Do When a Mailing is Not Being Received
There are many reasons that can keep a mailing from being received. If you or a subscriber are having issues receiving test or sent mailings through MA Professional, you can follow the steps below to help determine the problem.
- Search for the subscriber record in MA Professional to see if the mailing was delivered by navigating to Subscribers > Search > Details & History > Mailings. If the mailing is shown as being delivered, then the issue lies with the receiver's filter settings. If the mail is showing a bounce or block, refer to the Troubleshooting Deliverability Issues - Bounced Messages section above to troubleshoot further.
- It may be necessary to look up all recipients with that domain to see if just one or all are not receiving the mail.
- If it is only one recipient, then it is likely a user setting (ask them to add you to their address book or have them check their spam or junk folder for the mailing and move to the inbox). Refer to the User Inbox Preferences section of the Best Practices page for more information.
- If the issue is happening with all of the recipients, then there is a global issue with receiving the mail and you may need to reach out to that domain owner or postmaster (if it's a private domain) to have your IPs/domain whitelisted. Refer to the Whitelisting section below for more information.
- Check the content of your mailing; content plays a big role in whether or not mail is classified as spam. Test the content using our Virtual Inbox test or by sending an email to MailTester and checking the results. You can also check out additional tips here to avoid being classified as spam.
- If you haven't checked your sender authentication (which is similar to a license to send email), follow Step 1 in the Troubleshooting Deliverability Issues - Bounced Messages section above. This is another factor that affects your deliverability, so it is important to have this in place (and to rule this out as a potential cause).
Internal and Private Domain Deliverability Issues
When you encounter deliverability issues at a private domain (or your own domain for that matter), you may need to have your sending IP and/or sending domain whitelisted. Private email domains tend to have more aggressive filters in place when compared to other large email providers (such as Gmail, AOL, Yahoo!).
There are usually two ways in which an organization should think about whitelisting:
Whitelisting at Your Own Organization
When you use an outside mail server (such as Professional) to send mail on your behalf, you commonly see deliverability issues when receiving mail at your organization. This is because your mail server can identify mail sent outside of its system (using your sending domain) as being "suspicious" and either quarantine or flag as spam.
Contact your IT department prior to sending through Professional to have them whitelist your IPs and possibly our bounce address "informz.net." You can find your IPs by logging into your account and navigating to Admin > System Settings and then scrolling to the bottom of the screen.
If you continue to have issues receiving mail sent from Professional internally at your organization, it may be wise to reach out to your IT department to see if there is another filter preventing mail from being delivered (this could be content, sender authentication, too much mail sent at once, etc.).
Whitelisting at Other Private Domains
If you find that mail is not being delivered to the recipients' inbox at a private domain, you may want to contact the domain owner or postmaster to request to whitelist your Professional publish IP, informz.net, and/or your "from" address.
Keep in mind that whitelisting does NOT guarantee mail will be delivered to the inbox. Whitelisting is done by the mail receiver, and if the sender is not following best practices, the whitelisting in place may be ignored.
Understanding Blacklists and More
It's important to understand blacklists and their impact on your deliverability. There are three important list types that you'll want to understand in relation to blacklists:
Let's take a look at the different definitions, and what you can do to avoid blacklists.
A blacklist contains IP addresses and domains that are suspected of sending spam. Many email servers and spam filters filter mail based on whether or not the sender's IP is on a blacklist. Ultimately, blacklists help to filter out spam and protect the recipients.
A greylist contains the IP addresses and domains of bulk senders. Greylisting can be used by receiving mail servers to temporarily reject mail coming from bulk senders. They can be used to deter spammers because most legitimate senders attempt retry the mail that is rejected while many spammers do not. MA Professional automatically retries temporary errors to deliver mailings.
A whitelist contains IP addresses, domains, and email addresses considered safe senders at the mail receiver or spam filter levels. This can help identify legitimate mail to be received without being labeled as "spam" or "junk." Keep in mind that whitelisting does not always prevent mail from being classified as spam. If mail is sent with patterns characteristic of spam, it is still very likely the mail will be filtered.
How Does a Sender Become Blacklisted?
A sender is typically blacklisted due to sending mail to spam trap addresses, receiving complaints, spikes/dips in volume, spam-related content, etc.
How Does a Sender Avoid Being Blacklisted?
Unfortunately, getting blacklisted is common and often unavoidable. However, there are some things you can do to try to prevent future listings:
- Send only to engaged, opted-in subscribers
- Send at a consistent volume
- Include a clear unsubscribe mechanism on all mailings
- Avoid common spam triggers (avoid third-party link shorteners, spam trigger words, image mapping)
What Do I Do If I'm Blacklisted?
Many blacklists are temporary and auto-delist. However, some lists require remediation, which MA Professional monitors. Remember, it is up to the email marketer to follow sender best practices and maintain a good sender reputation!