We've covered deliverability a number of time in the past, and for good reason. It is probably the most important aspect of email marketing. If it doesn't drop into an inbox, you have wasted your time. Not only that, you can gain a 'reputation' with the filtering agent and make it more likely that your emails will be classed as spam in the future.
Deliverability is a big subject so there's no way it can be covered in one article, so let's look at just one factor: your email marketing list.
You need to collect, check and clean your lists in order to increase the likelihood of them passing spam filters. Let's take an obvious example. You buy in a list without checking its dependability. You send out your first email marketing campaign using the list. What is the likely reaction of the receivers? A rhetorical question as we all know that a few, some or many will class it as spam.
The next time you use your From address you will experience a higher rate of rejection as well as more people dropping you into the spam folder. At the very least you will lose the effectiveness of your From address and if you used it for those who had subscribed of their own free will, then some of those might well be lost en route.
Bought in lists can be an effective way to build numbers but you must take all necessary steps to verify their validity.
Other ways of irritating your subscribers is to be less than honest with them when they sign up. If they thought all they were to receive was a weekly e-newsletter then they too might look to classing you as spam. Many companies send an automated reply when a customer subscribes to an email marketing list telling them what they should expect and giving them a chance to unsubscribe, or perhaps change their classification.
Don't hang on to their legs. If they unsubscribe then accept their decision. By all means send an acknowledgement with the option of staying on your list. Some companies even include a special offer. If you pester them, they might become irritated and firstly, negate any chance of resubscribing and secondly, the spam button will be nearby.
It can be very useful to delete those who are inactive. Send them an email asking them if they wish to stay, perhaps annually, with either an option to unsubscribe or removing them from your lists if they do not resubscribe. Only pick those who haven't opened your email in a set period and leave the active customers alone.
Engagement is a factor in filtering emails. If they are not opened or responded to in any way, it will count against the sender.
Respond to your metrics. If a subscriber prefers plain text to html, then send them plain text. You might feel that all your time and expertise in creating the campaign is wasted, but the receiver is always right.
What you are after is a pristine list. More of your emails will be opened and responded to. All this helps with the spam filters. We'll go into greater depth in a future article.