Spam is a constant threat that comprises almost 80% of all email sent on the planet. In an effort to do our part and protect both our servers and customers, we have recently implemented outbound spam filtering. This page is to help those customers that are getting the error below in their emails:

550 This message was classified as SPAM and may not be delivered

Common Fixes for the Error:

Solution #1 - Ensure SMTP Authentication is enabled in Outlook

The Microsoft Outlook email client seems to be causing email messages sent through it to score higher than normal, causing emails that otherwise would be allowed through to be classified as spam. This is most commonly caused by not having SMTP Authentication set in the Outlook. Check out our article on Invalid HELO Names for instructions on setting that correctly. You should then be able to send normal emails properly via Outlook.

Solution #2 - Check your email content

Our email servers are using spam evaluation process that is set to the most lenient levels. This means it is difficult for your emails to be tagged as spam and prevented from going out unless they have a lot of features of a spam message. However if you are still getting caught by the filter, you will want to evaluate both the subject line and body content of the message to ensure there are not any references to popular spamming terms.

Solution #3 - Contact our Live Support Team

If you have attempted solutions one and two above and are still getting caught by the outbound filter, you will want to contact out Live Support team. When contacting them, please be sure to send the entire bounced email, including the bounce back headers. Forward the information to This email address is being protected from spambots. You need JavaScript enabled to view it. and our support team will then take the email and find its records in the filtering logs to see why it was blocked.

What is outbound SPAM filtering?

We have customizable spam filtering tools already in place for each account that evaluates incoming emails. Outbound SPAM filtering is a process where any outgoing emails will be checked as to the likelihood of the message beign spam. This is not customizable on an account level and is handled by your hosting server. It checks for multiple characteristics and assigns points for any it finds. If the email reaches a certain level, it is classified as SPAM and not allowed to leave the server. If you are receiving a bounceback with the error "550 This message was classified as SPAM and may not be delivered", then the email you sent has not passed the outbound filter.

Email to any recipient can always be determined to be spam based on content. The number of recipients for outbound emails are limited to 50, so it is not typically used as criteria in determining that an email is spam. The recipient field is only used as criteria for allowing or dis-allowing emails when the recipient has been explicitly placed on a blacklist or whitelist. This can be done in Spam Assassin.

Why are you doing this on outbound emails?

Outbound screening helps to preserve the reputation of our server's IP addresses. If an email server's IP gets enough spam complaints against it, it will be reported and blacklisted by a blacklisting service. Any email server that subscribes to that service will then block any mails coming in from that IP address. It is also possible that any emails coming from any of our servers will eventually be automatically being delivered to spam folders, regardless of the IP address of the server. As most of our customers do legitimate business online, it would be unfair to allow our server IPs to be classified as spam because of a few abusers, hence the outbound spam evaluation.

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n/a Points
2014-04-12 6:19 am

I am trying to forward a phishing email to and it gets rejected because it is obviously spam.

How is one supposed to do this as requested by American Express?

17,314 Points
2018-03-14 9:38 pm
Hello Len,

Probably the easiest thing you can do is send it as a graphic. Use a screen capture program (such as the one built into Windows or a Mac OS) and then send the graphic as an attachment to your recipient. The text will not be scanned by the email filters and they can look at it that way. Hope that helps!
17,314 Points
2014-04-12 10:42 am
Hello Len,

Probably the best thing to do is to export the email into a text file and then save it - make sure to include all of the headers. Save the TXT file as an attachment and then send it. If you have access to make the email into a PDF, then that's another way to attach and send it. You can also save the file as a TXT file and then make it into a file that can be shared via service such as Dropbox.

Hope that helps!

Arnel C.
n/a Points
2015-10-02 5:04 pm

I send out a monthyl newsletter when I try to send a test copy to my email address it's getting rejected as spam, how do I fix this?  Thanks

17,314 Points
2015-10-02 5:27 pm
Hello Terry,

Sorry for the problem with the newsletter. We would probably need to see an example of the newsletter that you're sending and the header for the email containing the bounce message. We would be able to investigate the issue in more depth. If you're sending the email out to a small number of people (under 50), then it shouldn't be a problem. If you're sending it to a large crowd, then you should be a distribution application or service. For example, phpList or if you can avoid the whole issue altogether and use a service like Mailchimp. MailChimp is free for the first 2000 subscribers. The added benefit of using a service is that it keeps the email load off of your hosting service.

I hope this helps to answer your question, please let us know if you require any further assistance.

Arnel C.
n/a Points
2015-10-05 2:16 pm

This change have quietly stuffed up a system I have been using to send forms filled in on my websites to an email address on that website. Yes the form details could be spam, even captcha cannot stop all of the spammers, but the point is that the email is sent to an email address belonging to the domain that it was sent from. So you clever people are rejecting a message sent to myself as spam. Rethink your thought process.

n/a Points
2016-02-15 9:50 pm
It doesn't resolve the problem that you are flagging my emails as spam when they are simply responses to people who emailed me first.
1,198 Points
2016-02-26 6:08 pm
Hello Regan,

How are you sending these emails out? You should be authenticating with the SMTP outbound server with your password. Does the email send if you send it from webmail?

Best Regards,
TJ Edens
n/a Points
2016-02-26 7:34 am

Some, not all of my messages I send are being labelled "550" - its only just started to do it in the last day or so. Annoying as these are not remotely spam but normal emails to clients

1,198 Points
2016-02-26 6:03 pm
Hello Scott,

How are you sending these emails? If you are using a desktop or phone mail client please make sure in your outbound server settings you are authenticating with the SMTP server via your password.

Best Regards,
TJ Edens
n/a Points
2016-07-14 2:41 am

I've had the same problem with the 550 error message on personal emails. I checked the spam word list, tried deleting some words or phrases that aren't on the list but still may be suspect, and it still won't send. I finally had to copy and paste  the e-mail into my yahoo account just so I could get it sent. Is that any way to do business? Here's the message. Please tell me why this is considered spam.

*** content removed by admin for security reasons ***
16,266 Points
2016-07-14 7:56 pm
Hello Eugene,

The software that filters the outbound emails is the same that you can use to filter your inbound email: Spam Assassin. This software is set to detect a specific number of spam points assigned to an email. If any outbound email has that number of points of higher, it will reject it.

There can be times when false positives occur, preventing emails that really should not be. Your case seems to be one of those. You will want to contact our Live Support team about this so they can take action for you.

Kindest Regards,
Scott M
n/a Points
2016-08-04 8:35 pm

Thanks for the information. I was able to experiment with content and subject line words. My e-mails were being filtered for various words of sexual content. I'm involved in some on-line dating activity and the content gets sexual sometimes. I feel like you guys are trying to be the moral police.

If you are responding to an e-mail you received and you are sending back to the same address then the mail should go through regardless of content.

12,339 Points
2016-08-04 10:52 pm
Thank you for your suggestion. Our servers use standard email filter settings. I recommend contacting Live Support (Solution 3 above), which allows them to look at your specific case, and identify a false-positive, or help get your emails delivered without being flagged.

Thank you,
n/a Points
2017-02-01 2:42 am

I ahve the same compaint as others.  I am replying to an email that was a previous reply to my email and then for some odd reason it was flagged as spam.  SUPER FRUNSTRATING!

17,314 Points
2017-02-02 1:05 am
Hello Frank,

Sorry for the frustration with the 550 error. The problem has to do with how legitimate email is being flagged as spam. We can either filter for spam or whitelist your domain. As per the article above, we need to have an example of an email going out so that we can determine if there is an issue of false positive identification with the content of your message. Please provide this information and we can move towards a resolution.

If you have any further questions or comments, please let us know.

Arnel C.
n/a Points
2017-02-21 5:44 pm

I am replying to business emails and have just found that they cannot even be sent as the message was classified as SPAM and may not be delivered.

I raised a helpdesk call about emails not working well over a week ago and did not even receive the courtesy of a response.


Surely this cannont be correct or a fair way to run a service. 



304 Points
2017-02-21 11:52 pm
Niyi, I'm sorry to hear that you've had this issue, but I'm happy to help! I would recommend reaching out to your email hosting provider again to assist you in resolving this issue, as they will need to address account specific information related to this.
n/a Points
2017-03-07 2:49 pm

Problem in your email body any text like chinese language error returns by your outlook not the remote server check without any body text and send test email.Email will go without any problem




n/a Points
2017-03-11 1:10 am
Can't cut paste the email you flagged - to two recipients, so it's clearly not spam!
Since I'm using Thunderbird, I even just retyped the email, and your 550 tool wouldn't even accept that. USELESS!!!
304 Points
2017-03-11 1:13 am
J, I'm sorry to hear that you're having this issue, but I'm happy to help! If your email contents are legitimate, I would recommend contacting our Support team and showing them what you are trying to send. They will review it, and if possible may be able to allow your emails to send as normal.

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