Technical and administrative requirements for sending email to Mail.Ru

These requirements were developed with consideration given to the standards developed by members of the global working group for counteracting spam, fraud and other forms of electronic abuse. 
Non-compliance with these requirements could lead to partial or full non-delivery of your email.

Technical requirements

  • All email must comply with RFC standards (for example, SMTP 5321; MIME 2045, 2046, 2047, 20482049).
  • Bulk emails must be indicated by "Precedence: bulk" in the email headers.
  • All mail servers connecting to Mail.Ru servers must have valid (real), meaningful, and not automatically generated reverse DNS records (rDNS, PTR). Additionally, the contact information for each IP address in WHOIS must be up-to-date and available. 

    Examples of rDNS records: 
            Correct rDNS: mail.domain.com 
            Incorrect rDNS: 231.2.53.243.domain.isp.com
     
  • All mail servers connecting to Mail.Ru servers must be appropriately protected against unauthorized or anonymous use. Be certain that your server is not a public proxy server or a public relay.
  • Ensure that all web forms on your websites are safe.
  • If you use scripts that send emails from web forms, be sure that they cannot be used to send spam.
  • Direct connection to Mail.Ru's MX servers from a dynamic IP address or home network address is not allowed.
  • Mail.Ru's MX servers must not be hard-coded in the sending servers' configuration files.
  • When using HTML in your messages, be sure that you form a valid HTML document. You cannot use potentially dangerous objects, such as ActiveX, JavaScript, VBScript, Java applets, frames or iframes, CSS connected to external websites, Meta Refresh, etc. Using these elements may lead to your distributions being blocked.
  • The use of external services (redirectors, link shortening services, etc.) in order to conceal information about the true destination webpage of any hyperlink in an email may lead to your distribution being blocked.
  • IP address and domain names may not be URL encoded in emails.

Administrative requirements

  • A distribution must only be sent upon the explicit and direct request or consent of a user (opt-in).
  • The text of every email in a subscription-based distribution must include the contact information of the organization sending the distribution, including a phone number and physical address.
  • Bulk distributions must have a simple and obvious way to unsubscribe. The unsubscription process must not require the user to perform complicated actions, such as entering or recovering a password, registering, etc. We recommend providing an unsubscription mechanism by including an easily noticeable link in each email in order to unsubscribe with a single click. Users must not be required to sign into a website in order to unsubscribe from a distribution.
  • Bulk emailers must not take actions to conceal, fabricate or distort a message's sender or delivery origin.
  • Information about the subscription, including how the email address was obtained, the subscription date and time, and the IP address from which the subscription was made, must be made available at the user's request.
  • Distributions must include information about the source of the user's email address, as well as their consent to receive the distrubution. For example, "You've received this message because you subscribed to this distribution on our website...".
  • Services performing subscription-based distributions must unconditionally remove subscribers from their database or take measures to suspend distribution to them if their email addresses generate an SMTP error (550 user not found). Tracking the validity of your user database is necessary towards maintaining a positive reputation as a bulk emailer.

User complaints, sending to nonexistent email addresses (including those that used to exist, but have since been deleted), the inability for the sender to receive failed delivery reports and being caught by Mail.Ru's spam filters can all affect a sender's reputation. Any sender with a negative reputation may be blocked from sending messages to Mail.Ru. A series of violations from one bulk emailer could lead to an IP address being partially or fully blocked at Mail.Ru.