HostArmada Web Hosting Knowledge Base

Knowledge is power! Use that power and achieve total and unconditional control over the Web Hosting Services!

Expaining the various exim status codes.

Exim is a regularly used MTA(mail transfer agent) used on Unix systems and is integrated with the cPanel service we offer. It is a versatile mailer providing a vast array of conveniences for managing both incoming and outgoing emails. Understanding and knowing about its status codes can help you solve basic email problems you are facing with your service. In this article, we will attempt to cover the most common reply codes and hopefully teach you a thing or two about them! The status codes can be classified into four categories.

Status Code 2.X.X - Success Messages 

These codes will usually make you smile and will assure you that everything is fine.

  • 211 - This status will show a message about the state of the server whenever a user requests help information.
  • 220 - Service is up and running! Typically the first message you would receive from a working server and the most expected one.
  • 250 - The equivalent of the HTTP 200 response code - OK! This status will be displayed each time a mail is received or sent successfully. 
  • 252 - Cannot verify the sender response code. The server will acknowledge the fact that the user is valid, but it cannot verify him. Delivery will occur, or the message will be relayed to a different server able to verify the sender.

Status Code 3.X.X - Informational

  • 354 - There is only one status code in this category, and it is triggered by when the server received the "From" and "To" addresses. It will then query for the body of the message.

Status Code 4.X.X - Persistent/Temporary Failure

These are status codes that can show up from time to time and last for an undefined period, due to temporary server faults on either the sender or receiver's end.

  • 421 - This status code could mean problems on either your server's end or the receiving server's end. Usually related to connectivity issues.
  • 422 -  This status code reports that the recipient's email box is full.
  • 431 - This status code indicates that the recipient's email server is experiencing storage or memory issues. It could be caused if you are sending a lot of emails concurrently or emails with big attachments. Our suggestion, in this case, is to lower the number of simultaneous mail-outs 
  • 450 - This status code indicates that the remote mailbox was not available during the delivery attempt. May present itself for various reasons such as the remote server being offline, corrupted mailbox, a problem with the sender's IP being blocked, or placed in an RBL(Realtime Blackhole List).
  • 452 - This reply code states that the requested action cannot be taken. You may observe this when the server has a problem with resources, such as memory or storage. Another common reason is the number of messages the server is trying to send out is too high.

Status Codes 5.X.X - Errors 

The most resented Exim status codes. Suggest an underlying issue with either the sender or the receiver's end.

  • 503 - This status indicates that you have failed to authenticate yourself in front of the SMPT server. Usually, it suggests that the username or password you entered is incorrect. 
  • 510 and 511 - Bad email address. You have typed in an address inside the "TO", "CC" or "BBC" fields that do not exist in the remote mail server.
  • 523 - Each mail server has configurations in regards to the maximum size of an individual message it can accept. This status code will be shown when the email you attempt to send exceeds this value.
  • 530 - This could mean three things 
    1. You need to authenticate yourself in front of the SMTP server or in front of the recipient's incoming mail server.
    2. The destination server has blacklisted your server.
    3. The recipient has a non-existent mailbox.
  • 541 - The recipient's server has rejected your message.  An antispam program on the receiver's end could trigger this.
  • 550 - This will most likely be the most regular error code you will see. Typically suggests an issue with the receiver's end, notifying you that there is no such email address. It may appear due to the remote server being down, or by the fact that your SMTP server's IP address is present in the FireWall.
  • 552 - Aborted Mail Action. Regularly caused by exceeding the storage of the receiver's server or the size of the message exceeds the inbound size boundary.
  • 554 -This is perhaps the worst status code you can see. It lets you know that the recipient's mail server considers that your message may be spam-oriented, or your server's IP address is blacklisted in one or more RBLs.

Was this article useful and on point?

Find out more about HostArmada entire range of optimized Web Hosting Services and take action today on improving your website Loading Speed, Security, and overall Stability!