GreenArrow Email Software Documentation

Common Error Messages

This page outlines some common errors seen in GreenArrow Engine, what they mean, and what you can do about them.

Error: “read wrong length for reply_header; reply_header = [[]]”

Symptom: Clicking on a campaign in GreenArrow Engine’s Sends page doesn’t load, and instead returns the error:

read wrong length for reply_header; reply_header = [[]]

Possible Solutions:

If this shows up immediately after clicking to view the stats there could be a service that is offline or some deeper system issue. This will require additional troubleshooting, and it is recommended that you contact GreenArrow’s technical support.

If the page tries to load for a little while (a few minutes) before reporting this error, it most likely occurred because the system is not able to process the SMTP delivery logfile records into an intermediate form (from which Engine’s reports are generated) fast enough. This can occur when the system gets behind on processing these, or more commonly when the system is constrained on Disk IO.

In this case there are two options to fix:

  1. You can give a higher priority to this processing by setting a higher percentage in this configuration file: /var/hvmail/control/logfile_processing_utilization (setting this to 100 will give this the highest priority).

  2. You can upgrade the hardware to disks that will provide higher Disk IO capacity, which would remove this constraint. After the hardware upgrade you will need to contact GreenArrow’s technical support to adjust your system to take advantage of this new hardware.

Error: Events are delivered with unknown in the email field

Symptom: The email address is not being sent via the event delivery, and instead you receive unknown. The SimpleMH click_tracking_id field may also be blank.


There is a cleaning process that runs to remove old files from the system which are used for identifying who clicked on what link. These are deleted after 60 days.

This means that anyone who clicks on a link that is older than 60 days, you’ll see unknown in the email address for the event.

The solution is to extend the retention out to a longer range. The only consequence of this action is that it will require more disk space. You can use the documentation here to adjust the retention.

Error: Connections to GreenArrow’s SMTP ports are failing

Symptom: Injecting emails to GreenArrow’s SMTP ports (typically port 25 or 587) are failing.

Possible Solutions:

If you are not able to make any SMTP connect, you’ll likely get an error like “Connection Refused” or “Connection Timeout”. This typically means you’re not even reaching GreenArrow’s SMTP service, and there is something blocking you somewhere between your injecting server and your GreenArrow server. These are the most common causes for the connection to fail which you may want to check first before starting an end-to-end check of the connection:

  • Are you connecting to the correct IP or hostname and port?
  • Is GreenArrow listening on the IP / Port that you’re trying to connect to?
  • Is the firewall open on both GreenArrow and the injecting server?
  • Are you using multiple firewalls on either side of the connection? If so, are the ports open on all of the firewalls?
  • Is the injecting server able to make SMTP connection to any SMTP host or is the issue limited to your GreenArrow server?
  • Does GreenArrow have enough available SMTP Connections? Check the SMTP service logs for the tcpserver: status - as long as it doesn’t continually show tcpserver: status: 100/100 you have available connections.

If you made it to the end of that list and you’re still not able to connect, then you may need to use a tool like traceroute to see where the connection is failing.

If you’re able to make an SMTP connection but you’re not able to inject a message, then you may see one of the following errors:

Error Solution
553 sorry, that domain isn't in my list of allowed rcpthosts (#5.7.1) You are not authenticated to send email through GreenArrow.
552 sorry, that message size exceeds my databytes limit Your email is too big. Either reduce your message size or adjust your databytes limit in GreenArrow

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