10 reasons to use an SMTP relay service

Posted: Friday, October 21, 2016
Posted by Ciara Noonan.


Getting email right is something many web hosts struggle with. All too often spam can sneak in – as it always does – and the balance between host, customer and their customers is disrupted. It’s not a matter of if, it is a matter of when. An SMTP relay service, such as MailChannels Cloud, can help protect your hosting company by ensuring outbound email is delivered safely and securely – protected from spam and phishing.

Here are 10 reasons to use an SMTP relay service: 1 Save your employees’ valuable time

When something (inevitably) goes wrong, it takes a lot of time and effort to get it fixed. It was estimated through a MailChannels survey that 25% of support tickets are caused by email delivery issues.* Your employees’ valuable time could likely be spent elsewhere more efficiently.

2. Avoid… Read More »

Hosting Your Own Email Might Not Be A Good Idea

Posted: Tuesday, October 04, 2016
Tim Evans ••(601)606-5177
Posted by Ciara Noonan.

As I’m sure you’ve noticed, self-hosted email has been in the news recently. Politics aside, a number of recent articles have encouraged ordinary users to take the plunge and mitigate the privacy and security implications of third-party email hosting by building and managing their own email service.

I’m sure these writers have their hearts in the right place, but the consequences of thousands of non-technical people taking it upon themselves to host their personal email are likely to be catastrophic, both for the users and for the wider email system.

Self-hosting email is certainly possible. The tools are freely available. Everyone has access to the open source software used by web hosting companies and dedicated email providers. But setting up a server with the right software is not the same as successfully using it to reliably and securely send and … Read More »

How Do Email Complaint Feedback Loops Work?

Posted: Tuesday, September 27, 2016
Posted by Ciara Noonan.

Many organizations spend thousands or even tens of thousands sending legitimate marketing emails every day. However, spam is in the eye of the beholder. A percentage of the people on any organization’s mailing lists may think of these marketing emails as spam.

It’s in the interest of marketers, email service providers (ESPs), and mailbox providers (MPs) to unsubscribe those users. Mailbox providers — the organizations that handle email delivery to users — and email service providers – for example, MailChimp – are highly sensitive to spam. MPs don’t want their users exposed to spam, and ESPs don’t want to end up on blacklists. Reliable email delivery is important for their business. 

What is a Feedback Loop (FBL)?

Feedback loops are one of the mechanisms by which the email industry attempts to make sure that users don’t receive email they do … Read More »

Top SMTP Error Messages – June 2016

Posted: Friday, June 24, 2016
Top SMTP Error Messages
Posted by ksimpson.

In 2012, we posted a list of the world’s most popular SMTP response codes. We are now pleased to present an update to the list. Using a slightly updated script, we

Processed email delivery logs from the MailChannels Cloud SMTP relay service; Picked up all the SMTP response messages representing permanent delivery failures; Did a bit of string cleaning to remove serial numbers and other random-looking identifiers; and, Associated each log line with the organization that generated the error. Here are the top rejection messages

(organized by the network that generates the error)

Organization Response Code Meaning GoDaddy ( 550 5.1.0 23.83.x.y is not allowed to send from <> per it’s SPF Record. Please inspect your SPF settings, and try again. IB508  <> The message was rejected because the sender domain ( does not authorize the sending IP address in… Read More »

Why Outgoing Spam Filtering can and should be done transparently

Posted: Friday, April 29, 2016
Transparent Outgoing Spam Filtering
Posted by ksimpson.


Web hosting providers can find it challenging to ensure a clean IP reputation. Unfortunately, the internet itself is not free of misinformation about outgoing email filtering. In this blog post we challenge three suggested alternative methods for cleaning up your IP reputation

Three suggested alternative methods for cleaning up your IP reputation


1. Blocking port 25:

Web hosting clients should not be restricted from using a port that is lawful to use (unless you’re spamming, of course). Most providers we talk to would not consider blocking port 25, for fear of losing customers. Still, this option is often promoted as a quick solution to the spam problem.

Here’s why port 25 blocking is not a good idea:

Lawful customers are inconvenienced – Most web hosting clients are not spammers. By blocking port 25, you’re removing functionality that they… Read More »

MailChannels launches Reseller partner program

Posted: Tuesday, March 15, 2016
Posted by dliao.

We know you want new, value-added services to bring to your hosting customers. And we know your team spends a lot of time resolving email issues. So we’ve designed a single, easy solution to meet those two challenges: the new MailChannels Reseller partner program.

Email is our sole focus at MailChannels. It’s important to us that we provide our customers with the best anti-abuse tools for your business. We’ve taken our carrier-grade on-premise software and extended it via MailChannels Cloud so that web hosting companies of all sizes can benefit from the same techniques.

This program provides our Reseller Partners with the tools, training, and resources needed to make it simple and profitable to offer email security products to your hosting customers.

MailChannels Reseller Partners are able to: Provide exceptional email deliverability for their hosting customers Earn ongoing revenue from… Read More »

MailChannels Named Top Tech Company in Rocket Builders’ “Ready to Rocket” List

Posted: Thursday, March 03, 2016
Posted by dliao.

This week, the Vancouver-based consulting firm Rocket Builders released its 14th annual “Ready to Rocket” lists. The “Ready to Rocket” lists identify British Columbia technology companies that are positioned to grow quickly. We’re proud MailChannels landed a spot on the Information and Communications Technology (ICT) list.

This annual list is a predictor of privately-held tech companies that will likely experience significant growth, venture capital investment or acquisition in the coming year. MailChannels is growing fast – in the past year, we experienced explosive revenue growth, our headcount doubled and we secured a new brick and timber office in historic Gastown to accommodate our growing team.

“I’ve had the opportunity to interview most of the companies on our lists,” said Reg Nordman, Managing Partner at Rocket Builders, “The diversity of solutions, maturing skill sets of management and the resulting increased ability … Read More »

Tackling Greylisting in MailChannels Cloud

Posted: Thursday, December 10, 2015
Posted by ksimpson.

MailChannels Cloud sends enormous volumes of email through a large and complex infrastructure that spans the globe. But recently, we began encountering a serious challenge from a relatively old and yet still commonly used anti-spam technology called “greylisting”.

What is Greylisting?

According to Wikipedia, greylisting is an anti-spam technique in which the “mail transfer agent (MTA) … will ‘temporarily reject’ any email from a sender it does not recognize. If the mail is legitimate the originating server will try again after a delay, and if sufficient time has elapsed the email will be accepted.” Greylisting can be an effective defense against spam originating from simplistic botnet SMTP clients, which do not have an internal message delivery queue and cannot retry delivery if the first attempt fails (as it does when the receiving server is implementing greylisting). Legitimate email senders always … Read More »

Should I build my own mail server?

Posted: Tuesday, October 06, 2015
Building my own server
Posted by ksimpson.

With Edward Snowden’s revelations about government snooping into our private email, some technically-minded folks have considered setting up their own mail server in the hopes of staying clear of prying eyes.

Is building your own mail server a good idea?

Probably not. And here’s why.

Setting up a secure email server takes a great deal of expertise and effort.

You need to master a variety of protocols, from DKIM and SPF, to TLS. You also need to build a capable spam filtering system to protect yourself from email-borne offers and malware, and you need to contend with the nightmare of outbound delivery and IP blacklisting. When you’ve done all this, you also need to make sure the server is constantly kept up to date with the latest security patches, lest a global network of well funded state-level hackers gain access … Read More »

Spamhaus responds to SoftLayer’s Brazilian problem

Posted: Thursday, October 01, 2015
spam targeting Brazilian recipients
Posted by ksimpson.


Spamhaus, the world’s leading IP reputation advisory service, today released an analysis of an ongoing spamming issue at IBM’s SoftLayer web hosting subsidiary. According to Spamhaus, spammers have been targeting weak security measures at SoftLayer to obtain large numbers of IP addresses from which to send spam targeting Brazilian recipients. As a result of the spamming activity, Spamhaus has listed several hundred IP addresses owned by the provider under the common heading “Massive source of malware-distribution spam”.

Spammers routinely target web hosting providers like SoftLayer in an effort to obtain new resources from which to send spam campaigns. As Spamhaus and other IP reputation outfits block the offending IP addresses, spammers are hard at work exploiting any weaknesses in the provider’s security posture to obtain more. In the present situation, according to Spamhaus, the provider is not doing enough … Read More »