Best practices for sending emails to many recipients

This article provides best practices for sending legitimate email to several
recipients through the Rackspace mail system.

If you received a bounce message when sending an email, see our list of
common email bounce messages for more


  • Applies to: Administrators and Users

For more information on prerequisite terminology, see
Cloud Office support terminology.

Best practices

For a video tutorial, see Rackspace Email - Spam Flags: Best Sending Practices.

Sending email to many recipients is a common practice of spammers. As a result,
most email providers have strict rules about this practice because it's hard to
distinguish your email from typical mass marketing, newsletter, and other
unsolicited mass email content.

To ensure that your emails reach their destination, we recommend that you use
the following practices:

Bulk email

Rackspace Cloud Office does not offer bulk email services. To ensure that your
bulk emails are not blocked, use a reputable bulk email service to send out your
content. Reputable email service providers deliver your bulk email in a way that
mail providers accept as good mail. Following are examples of reputable email
service providers:

Note: If you use Rackspace Email to send emails to a large number of
recipients, respect the mail requirements listed in our Acceptable Use


Ensure your recipient lists are current and accurate. Sending emails to a
large number of invalid recipients is a clear indicator of spam. Also, mail
providers and ISPs can use common invalid addresses as spam traps. Sending mail
to these spam traps can result in them blocklisting your domain.

Use confirmed opt-in practices when collecting email addresses for mailing
lists. Doing so reduces the chances of being reported as unsolicited. Unsolicited
mail is more likely to be marked as spam by recipients, which leads to content
filters flagging the sender as a spammer.

If you send email newsletters or communications to your customers, give them a
way to remove themselves from your mailing list. Typically you can do this by
providing an unsubscribe link in the message or with reply-to instructions. The
law requires this option.


Maintain a safe and reputable business website that includes easy access to any
privacy policies and contact information for your business. Spam filter
providers often audit high-volume senders by visiting their websites, which can
be a factor in determining whether you are a spammer.

If you allow other companies to include references to your business, ensure that
they are reputable. If they send out spam with your company information
referenced in those emails, systems could flag your domain as being related to

Message content

We recommend that you follow our person-to-person best practices when creating
message content. For more information, see Best practices for sending person-to-person email.

Note: Rackspace strives to maintain the best possible reputation with other
mail providers and the email industry. Our Anti-Abuse and Acceptable Use teams
work diligently to protect our users from abusive email. An important part of
helping us maintain our reputation is helping you send good email.