Email provider · 5.x.x permanent failure
Every SMTP 550 response on record from Mail.ru (mail.ru), with the verbatim text, the enhanced status code, a severity rating and a plain-English fix.
The mailbox is unavailable and the message is rejected for good. This is the catch-all permanent failure, covering everything from an unknown address to an authentication failure to a reputation block, so the wording after the number is what actually tells you the reason.
smtp;550 Message was not accepted -- invalid mailbox. Local mailbox [email protected] is unavailable: account is disabled
The address does not exist, or is no longer active, at this provider. Remove it from your list and check for a typo in the local part or the domain.
smtp;550 spam message rejected. Please visit http://help.mail.ru/notspam-support/id?c=7y4ytdHbuOGv3O50NYTwpz1F-TVIpnactxtFPeFQSDYMAAAAaKgAAOX_3hE~ or report details to [email protected]. Error code: ###. ID: #
The receiver's spam filter scored the message above its rejection threshold. Review the content and links, build sending reputation gradually, and only mail people who asked to hear from you.
smtp;550 Message was not accepted -- invalid mailbox. Local mailbox [email protected] is unavailable: account is disabled
The address does not exist, or is no longer active, at this provider. Remove it from your list and check for a typo in the local part or the domain.
The mailbox is unavailable and the message is rejected for good. This is the catch-all permanent failure, covering everything from an unknown address to an authentication failure to a reputation block, so the wording after the number is what actually tells you the reason. At Mail.ru, it is a permanent rejection, and the specific reason is in the enhanced status code and message text of each response below.
Match your bounce text to one of the responses below and follow its guidance. Recipient-side wording means fix the address. Authentication or reputation wording (SPF, DKIM, DMARC, blocklist) means fix your sending setup, and check Mail.ru's postmaster documentation.
