Proper testing will give email marketers a competitive advantage when it comes to delivery and engagement. A message that is delivered to the inbox and is displayed properly when opened will always increase the effectiveness of any email marketing campaign.

Using past delivery as an accurate indication of current delivery is a trap. Mail filters are constantly being updated to help squelch the constant inundation of spam. Using simple testing methods will help email marketers be proactive by making changes before messages are sent, rather than after.

• Send to email accounts created solely for testing. All the big ISP’s offer free email accounts, so open one or two accounts per ISP. Sending to this list of addresses can provide insight into whether the message is going to the inbox, bulk folder, or is being filtered by the ISP. These test accounts are also an excellent way to check message rendering, and to verify that the message’s ‘call to action’ is above the scroll bar fold. Sending to these seed addresses before, during, and after a mail campaign can be very helpful in gauging overall deliverability to major ISP’s.

• Another good way to test delivery is by sending a couple of smaller mailings before reaching out to the entire audience. Waiting a couple of hours between sends will help with overall delivery and allow for adjustments if there are delivery problems.

• A high spam complaint rating will almost certainly get messages directed to the spam folders, and nothing will generate spam complaints faster than an unsubscribe link that is hard to locate, overly involved, or not functioning properly. A quick test message to a personal account can quickly check to verify that the unsubscribe process is easy to find, easy to use and working properly.

Testing is not only important for delivery. It is also critical to insure that your audience has a positive experience once they receive your message. Nothing drives away a potential engaged audience member than a message that can’t be read or a call-to-action that can’t be acted upon.

• Spend a couple of minutes and make sure that all links work correctly and all images look OK. Checking from a network connection outside of where the message is being designed can help to verify that links and images are not only available within the local network.

• Give your message the six-second test. Since most messages are given the average of six-seconds or less, it can be helpful to have someone view your message for six-seconds and then ask them what they remember or what caught their eye. If the important elements or the call-to-action is not being recalled then the message might need to be modified.

• Several email clients now display messages with images turned-off by default, requiring the message recipient to take action before images are displayed. Checking the effectiveness of a message without images displayed can be extremely helpful. If the call-to-action or critical contact information is not being rendered it is useless.

• Test to a mobile device group. With a rapidly growing number of people checking their emails on mobile devices, marketers should know exactly what their messages look like on these devices. Setting up a test group of co-workers with various mobile devices can help to insure that enough of the subject is being displayed – some mobile devices will truncate subject lines. It is good to know if devices are still displaying a text version of the email message (marketers should always have a text only version). Keeping the message short and limiting image size will also help message viewing.

Remember the quote, "An ounce of prevention is worth a pound of cure"? Maybe Ben Franklin was trying to tell email marketers that it is better to try to avoid problems in the first place, rather than trying to fix them after they arise.