Cannout Send Outgoing Email

There are many reasons why an email cannot be sent. Here are the most common reasons and potential solutions.

No Internet Access

Outlook or your computer are having a hard time keeping up and need to be restarted.

Setting up a new computer, phone, or email client?

Check the outgoing email settings this is the most common issue. The email server requires all outgoing emails to be authenticated to a user account. This is necessary to prevent malicious spammers and systems from using the email server as their private spam sending machines. It means both your username and password must be authenticated before we will accept and send your email.

The following lists the points to check and the most common systems:

Internet Service Provider (ISP) Blocking emails

It has become common practice for ISPs to block emails on a certain “port number”. Without getting overly technical, a port number is what makes certain things work on the internet: email, websites, multiplayer video games and the like. It also powers your business on the web.

This challenge is most common on DSL internet providers like Qwest and AT&T. If you suspect your ISP is blocking email, there are two ways around this:

  1. Change your port number from “25” to “587” for outgoing email or use
  2. Call your ISP and request that they unblock port 25

Anti-Virus Software Blocking emails

If you have an anti-virus or internet security software on your computer, it might cause some problems with blocking legitimate emails. Usually making some tweaks to the anti-virus software can fix this problem. The fastest way to test this is to uninstall the program from your computer and restart, and then try to send a message again.

To get around this problem, most anti-virus software companies offer direct support for modifying the program to get it to work correctly with your email program. Another work-around is to use our Webmail system.

Less Likely

In very rare situations, email services will be unavailable for short periods of time. If this is the case, we will provide an update here on the Helpdesk home page.

I got a notice saying my email failed to be delivered.

Email messages sent from your computer go to our server, out through a spam filter, then through a series of routers to get to the recipients server, then finally up to the recipient’s computer or phone or whatever. There are possible bottlenecks along the way, any email server can only accept so many connections at a time and sometimes this delays delivery or receipt of an email.

Basic timing is as follows:

  • First Notice – generally at 24 hours
  • Last Notice – after four days, attempts stop and new emails to the same destination are rejected as well until the server is back online.

More information…

The SMTP RFC 5321 specifies a sending server must queue messages which cannot be directly delivered because of a temporary failure at the receiving end. Therefore in case of temporary issues with the email infrastructure, emails will not be bounced immediately but are instead queued on the sending server(s) and automatically retried for delivery. In case of downtime of the destination mailserver, messages are only accepted for delivery by the filtercluster if the recipient is known to be valid. Valid destination recipients are cached up to 96 hours.

When a destination server cannot be reached for 4 days, all messages will be bounced after 4 days and no new email will be accepted/queued until the destination server is back online. This 4 day period is conform the SMTP RFC. The reason it’s not longer than 4 days, is because it’s important for the sender to be aware that delivery of their message has been failing for 4 days so they can try and contact the recipient in another way.

As always, we’re here to help! Please contact our helpdesk and we help you through the issue.