Follow deliverability best practices

Having a good IP address and domain reputation is impotant to, so be sure to track your reputation using’s sender statistics program. does not use third-party reputation-based spam filters. It determines an aggregate reputation score from subsidiary data provided by data partners, engagement metrics and complaint rates. places a higher trust level in senders with better sending reputations. The higher the trust level, the more likely that email will be placed in the inbox. 

Best practices 

  • Sign up all IP addresses with’s feedback loop and suppress all complainers from receiving future email. sets the following thresholds for complaint rates based on your monthly volume:

Messages per month

Complaint rate limit

up to 10,000


up to 500,000


up to 10,000,000


up to 50,000,000


over 50,000,000


  • Use a confirmed opt-in (COI) consent method. With every subscription request, require the user to confirm their intent to receive email from you by sending them an email with an activation code.
    • Ensure the confirmation email is not used for promotional purposes. considers confirmation mails to be purely functional in nature and not an opportunity to market products or services.
    • Reminders about incomplete registrations should not be sent for longer than a three-month period after the initial registration and the total number of reminder mails should not exceed two.
    • Save all subscription request information including the date and time, IP address and browser. Saving this information can provide proof of consent to when mediating deliverability issues.
  • Do not purchase email lists or engage in list harvesting techniques. Email addresses acquired in this manner are a high risk of causing subscriber complaints, containing unknown users and containing a high number of spam traps. Many spam trap services purposely plant email addresses around the internet to catch senders involved with this type of practice.
  • Remove all unknown users from your email list after one bounce.
  • Be clear about what email the user will receive and when they will receive it at the point of sign-up. Clear disclosure helps increase the likelihood your email is not perceived as spam.
  • Use a familiar brand name in the friendly-from address and in the content so that subscribers can easily recognize you.
  • Use IP segmentation. Separate bulk email traffic from your corporate email with a different IP address. You may also see benefits at by separating transactional email from marketing email onto separate IP addresses.
  • Authenticate your email with Sender Policy Framework (SPF),  DomainKeys Identified Mail (DKIM), and Domain-based Message Authentication, Reporting and Conformance (DMARC). Using these authentication methods successfully helps have more trust that you are a legitimate sender.
  • Ensure your email and web servers cannot be used as an open relay or open proxy.
  • Do not use a dynamic IP address or will block your email.
  • Do not use potentially harmful HTML objects such as Active X, Javascript, VBScript, Java applets, frames, or iframes, etc.
  • Do not use a link shortening services such as These link shorteners often appear on blacklists. may perceive the use of a link shortener as an attempt to hide the actual URL destination.
  • Include your contact information with every email, including a phone number and physical address.
  • If you send invitations to email addresses based on an import address function, be sure you are following’s guidelines.
  • Engagement: considers engagement to be a good indicator of the relevance of a sender's messages. The abuse desk defines spam as a message that the user is not interested in or does not want to receive. It tracks how many of a sender's messages were deleted without being opened. If the deletion-before-open rate is high, a sender's reputation score suffers.
    • Large volume senders, like social media sites, that send notifications are the one exception. Most users delete the notifications without reading them, but still want to receive them.
  • Senders also must comply with all Request for Comment (RFC) standards relevant to email. Sender Domain Name System (DNS) records should be valid and the Whois record should be up to date. Incorrect configuration of Mail Exchange (MX) and pointer (PTR) records could cause mail to be rejected at the gateway.
  • Sign up for the Return Path Certification whitelist. Email marketers whose data management standards and sending reputations qualify for Return Path Certification, as well as those included on Return Path's whitelist of trusted senders, improve their ability to deliver messages to
  • Provide a simple way of Unsubscribing. considers it to be one of the most important aspects of emailing best practices and requires the process to be as simple as possible. Subscribers should be able to unsubscribe with one click without authorization. It must not require passwords or the completion of forms, and suppression of the email address should be immediate.
  • Do not send viruses or content with links to websites known for distributing malware.
  • Ensure your content image server does not contain viruses or malware.


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