Important Strategies for Increasing Email Volume During COVID-19

April 01, 2020
Written by
Will Boyd
Opinions expressed by Twilio contributors are their own

Important Strategies for Increasing Email Volume During COVID-19

As COVID-19 continues to disrupt the world, you might need to send more customer emails for new and unplanned reasons. This could very well result in a volume increase that is out of the norm for your brand. This can be risky because, when it comes to email delivery and particularly inboxing, there is no substitute for gradually increasing email volume over time.

However, we know that’s not always possible-especially in the age of COVID-19. To help, we compiled some recommendations for launching a new mail stream quickly or sending significantly more email than you were before COVID-19.

Important Qualifications

The following recommendations are for transactional emails or other critical COVID-19 messages, not marketing updates. The more your messages seem to resemble marketing communication, the more they are likely to be filtered or viewed as spam by both mailbox providers and recipients alike. When you're creating your COVID-19 customer emails ensure that you:
  • Use a very clear subject line such as “statement on Coronavirus/COVID-19”
  • DO NOT include any marketing content in the email
  • DO NOT use engagement with this campaign as an interest in receiving your marketing messages.
  • Do not send to your entire customer database unless they are directly impacted by changes to your business operations due to COVID-19. - Send to active customers that are likely to obtain value from understanding your brand's approach to the subject matter. - If you must send to your entire database, ramp email volume gradually and target your most engaged recipients first.
  • Keep in mind, people are unlikely to look to your brand for information on the virus. You should avoid contributing to inbox clutter and general noise, this could prevent critical updates from reaching your recipients.

Authentication matters

Utilizing dedicated IPs helps isolate you from the bad habits of other senders. Use consistent branding (website, DKIM, SPF, From Address) that ISP’s and your subscribers are already familiar with.

If you have not been actively sending email at high-volume for the past 30-days, you will want to gradually introduce your emails to mailbox providers through a warm-up process. For more information, please see our IP Warm-Up Guide.

Segmentation strategy

No matter the reason for the volume increase, when possible it is always best to split your campaign over as many days as possible. For best results, we recommend front-loading your most engaged recipients for the first few days of the campaign and gradually introduce your less-engaged recipients each day after.

For Non-Microsoft email addresses, split your campaign into 5 days:
  • Day 1: Only send to addresses that have opened or clicked another message from your brand in the last 90 days
  • Days 2-5: Only send to addresses that have opened or clicked another message from your brand in the last 180 days
  • Days 6+: Gradually add in older recipients, keeping an eye on your open rates at each ISP to make sure that your deliverability remains stable
When considering what your brand or organization will be sending during this time, it is more critical than ever to create content that is valuable to the recipient. Some examples of important messaging types are:
  • Cancellation of an event or changes from an in-person gathering to a virtual one
  • Changes to your business hours
  • System outages or delays in service due to staggering your workforce to prevent the spread of the virus


These guidelines are meant to help you minimize email delivery disruptions as you increase your volume quickly or introduce a new mail stream to the mailbox providers. The more you can avoid sudden volume spikes, and the more recipients find value in your messages, the fewer delivery problems you will encounter.

In the coming days, we will be providing more guidance around sending marketing messages during these tough times. For other tips about how your business can handle the COVID-19 crisis, check out Twilio's Field Guide to COVID-19 Communications. 

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