Best practices for a perfect mail delivery

Since Covid, working remotely and using email to communicate has been given an enormous boost. According to statista.com the number of sent and received emails per day worldwide crossed the 300 billion threshold in 2020 and will continue to grow by more than 20% within the next 3 years. Never before has the ability to send mass-emails been as important to the market research industry as it is today. Email provides a cost-effective, quick, easy way to reach out to a large groups of potential survey respondents and its’ efficiency can be accurately measured.

With this increase, email providers such as Google, Microsoft and Yahoo are now challenged more than ever to improve their systems and help their users to prioritize and categorize email traffic using machine learning. For panel companies, this means that more invitation, registration and confirmation emails to panel members end up in spam folders without users actually noticing. Don’t despair, there is a lot that can be done to avoid this happening.

We have put together 15 tips to assist you to keep your mailer healthy and help emails reach the target inboxes.

Follow the (local) laws governing email marketing

Make sure you follow the laws that govern digital marketing communications like the CAN-SPAM Act and GDPR which outline the practices you must use when sending commercial emails.
The CAN-SPAM Act defines spam email as any message which you:

  • Send without the recipients permission.
  • Send without including a mailing address.
  • Send with a deceptive subject line.
  • Send without including a way for recipients to opt-out.

Make sure you familiarize yourself with the laws of the countries you are targeting with your email campaigns. A good example is Germany, which is part of the GDPR territory but has partially superseding stricter rules with harsher penalties.

Ask your panel members to whitelist your email address

Mail service providers such as Microsoft, Google and Yahoo! try to make sure that their email programs don’t mark emails coming from people in your contacts as spam.

Ask your panel members to whitelist your emails by adding your “from” address to their contacts or list of safe senders. We recommend to include whitelisting instructions in the first welcome email you send when someone joins your panel and occasionally reach out to your members with these instructions e.g. via newsletters.

Use a mail relay with a good reputation and controls

Spam filters take a close look at the IP address associated with the sending email address and see if there are any spam complaints associated with it. If there are, then legitimate email addresses can get flagged simply due to association.

To make sure this doesn’t happen to your emails, the Q One Platform is working together with Socketlabs as preferred mail provider. When renting a dedicated mail server through Q One our customers get a whitelisted IP address with a good reputation which means that all mail traffic and behavior of  our clients doesn’t influence the email reputation of another Q One customer.

Socketlabs has features built in to help you avoid other common spam triggers and help you to get a deeper understanding of the efficiency of your email campaigns. This information can help you to improve your database and therefore help you to reduce costs and increase your margins.

Check your email content thoroughly

Modern spam filters are much more sophisticated than they used to be. Whilst in the past it was enough to avoid using specific “spam trigger words” modern spam filters will drill much deeper into your emails and their content. Spam filters analyze the content of your emails not only on wording but also on missing and broken code. A lot of typos, grammatical errors, broken links and images with no alternative text can all be a red flag for spam filters. Also make sure that you don’t write subject lines that sound like spam.

We recommend using programs like Mail Tester to check and tweak your emails and especially your survey invites, before sending them out. Create a test account on the Q One Platform using the test email addresses Mail Tester provides you to test your onboarding emails and survey invitations.

Remove abandoned email addresses from your panel

One metric that spam filters use to catch errant emails is to look at how many of the emails to which you are sending are actually active. If the percentage is too low, then that can be a sign that you’re sending spam email content.

To ensure this doesn’t happen, you should keep your panel updated and remove inactive and invalid email addresses. If someone hasn’t opened your invites in a long time, then it’s probably safe to remove them from your panel and when an email address is flagged as ‘permanently failed’ you should remove it from your panel directly. You can think of this like pruning a tree. You cut away small pieces in order to ensure the overall continued health of the organism.

The Q One Platform automatically deals with abandoned email addresses and flags them as ‘Unresponsive’. A panel member is set to status “Unresponsive” once this person has been invited to multiple projects (the setting can be changed in the panel settings) but has never replied to an invite by starting a survey or even declining it. If the “Unresponsive” setting is set to 10 it means that members who don’t respond to the 10th project (not email invite) are marked as “Unresponsive” and can no longer be invited to surveys. Most common reason is a problem with the email address (permanent failure) or a member has marked an invite as spam.

If you don’t have the time and resources to check your panel on activity and remove abandoned accounts feel free to contact the Q One Tech support team. We’re here to help.

Use spam checking and email verification tools

We briefly touched on Mail Tester, but there are other applications that will help you to keep your mailing lists clean and improve the content of your email campaigns.

Emailable offers various tools to check and rate your emails but also to verify the validity of email addresses in your panel. Kickbox is a service that lets you easily bulk check your email lists and tell you if email addresses and email domains are valid. If you search you will find many more services that can be of help. Q One Tech is working on various integrations to help you keep your mailing lists clean. Watch out for more information in our future newsletters.

Avoid spam traps

Honeypots or so called ‘Spam Traps’ are email addresses that are used solely for the purpose of identifying spammers by an email provider or another organization. Even when you’re doing legitimate outreach, there is still a chance of ending up in a spam trap.

There are three types of spam traps:

  1. Pristine: emails that have never been used for any other purpose.
  2. Recycled: emails that have once been used by a person but have since been repurposed for a spam trap.
  3. Emails that are purposely misspelled.

Sending an email to a spam trap can cause IP or domain to be list denied, causing a ton of damage to your domain reputation and subsequent deliverability.

Avoiding spam traps is not difficult:

  • Avoid emails that contain typos.
  • Never purchase an email list since they often contain outdated information and emails possibly repurposed to be spam traps.
  • Monitor your panel closely and remove abandoned accounts.
  • Set the ‘Unresponsive’ setting to a low number and accept the fact that members are set to ‘Unresponsive’.
  • Check the Q One Platforms ‘Once responsive’ report and use it to clean your panel.

Have a clear sender address

Your sender address is what appears in the “From” field when someone looks at your email. If you have a sender address that just sounds suspicious, you run the risk of your email getting flagged as spam.

Stick to either a person’s name or your company name. Not only is this helpful for keeping you out of spam but it’s also more personal and not associated with automatic emails. The Q One Platform allows you to have different ‘from’ email addresses for different purposes. For each ‘from’ address you can define the “Friendly Name” (e.g. “MyCompany Support”) which shows in a mail program’s email overview, the email name (e.g. “support”) and the email domain (e.g. “@mycompany.com”) – Example: MyCompany Support [email protected]

Furthermore, it is even possible to have different ‘From’ email addresses per project and you can also make the email “Friendly Name” dynamic to always use the lead project manager’s first and last name.

This way it is very easy to send personal invites and with a clear sender to your panel members.

Always send emails from an existing sender account

Whilst it is important to have a clear sender in the From field, some mail programs will flag emails as spam when the from address doesn’t exist. We noticed a huge difference depending on the mail program. Whilst Gmail often accepts emails coming from email accounts that do not exist so long as the SPF record, DKIM and DMARC are okay, Outlook will mark these emails as spam. Especially when you use the ‘Email sender per project’ option, this is something to keep in mind.

Email your panel members regularly

If you only send an email every couple of months, then you risk panel members forgetting who you are or why they joined your panel in the first place. If this happens, they may unsubscribe or even mark your email as spam when they do finally hear from you.

To prevent this, stay in regular contact with your panel members and try to keep them engaged. Monthly newsletters, quick polls and best wishes to (birthday, regional holidays, etc.) are a good way to interact with your panel members and keep them engaged. Of course, you should always provide value when you send an email, don’t just email panel members with a certain frequency because it’s “best practice” to do so.

Make it easy to unsubscribe

Not only is the option to unsubscribe from your panel and therefore your mailing list mandatory for GDPR and the CAN-SPAM Act, it is also something spam filters will flag if missing. Whilst our mail system automatically adds the option to unsubscribe from your mailing, our default survey invitation and other default system emails contain the option to opt out from your panel. Make sure to include that option (search and replace field: “{Unsubscribe}”) or add an equivalent to your emails (e.g. link to a custom unsubscribe form). Respect your panel members request to unsubscribe from your mailings or your panel as soon as possible.

Target your invite mail campaigns

Make sure you send out invites to members who meet the requirements for your studies and are less likely to screen out. Mail blasts might give good results on a short term but on a long term panel members will be less likely to open your emails if they keep screening out of your surveys. Less engagement with your emails will inevitably result in a lower domain reputation and effect the deliverability of your emails.

Improve your domain reputation

Domain reputation is a term that refers to the well-being of your email domain. Similar to a credit score, it affects the way in which email service providers view your domain. It also directly ties in with your email deliverability: a bad domain reputation means low deliverability and vice versa. There are three main aspects on domain reputation:

  • Scores that can be tracked by the mail provider: Mail providers track what happens with the email traffic from the sending mail server to the receiving mail server. Systems like SocketlabsSendgridAmazon SES evaluate the traffic and use the information to evaluate your mail score. It is important to take a close look to these evaluation points and use the information to clean your mailing lists and panels. Items that are tracked are:
    • Email is delivered
    • Email delivery failed temporary
    • Suspension:
      • Email delivery failed permanently
      • Email was marked as spam
      • Email recipient unsubscribed
  • Trackable mail engagement: It is possible to add custom tracking to emails when using a professional mail provider. When using a dedicated Socketlabs account with your Q One Platform license, the Q One Tech support team can consult you regarding that. The custom tracking links not only track mail opens but also clicks. With this information it is possible to tweak and improve your email invites and measure what effects different mail designs and messages have on efficiency of your survey invites.
  • Email engagement after an email was delivered: Mail providers can’t look into the mailbox of a recipient and therefore can’t report back what happened to an email after it has been delivered. A receiving mail server will report an email as delivered, even if the mail program moved your email into the spam folder. Companies like Allegrow developed systems that can predict the outcome of mail campaigns after emails have been delivered and engage with your emails to improve your email domain reputation and therefore deliverability.

The more panel members engage with your emails, the better your domain reputation therefore the better your deliverability.

Warm up your mailer

Older email domains have a naturally higher domain reputation simply because they have been sending out quality emails for a long time. If your email domain is new, blasting out your campaigns on day 1 is the fastest way to destroy your domain reputation.

Warming up your email domain is very simple: Start sending emails at a low quantity at first and slowly increase that number week by week. This will help you maintain a positive domain reputation and slowly increase it as time goes by.

Additionally, you can make use of an email warm-up service, such as Lemwarm to increase your sender reputation over time or recover it after spam complaints.


To ensure your email domain is good and your email deliverability excels, it is important to work on all the tips and best practices above and once you are used to it, you will be surprised with how just a little effort can significantly improve your results.



Related Posts