Recently, a member of our marketing team was preparing an email that contained a short link created by a third-party URL shortening service. But just prior to sending, the message was flagged by our ESP as "likely spam" because of the link.

That raised an important question: Are short URLs generated by third-party services being blocked by major ESPs and ISPs because of potential spam problems?

The short answer is no: We asked deliverability experts at several ESPs, who reported no widespread blocks against short URLs. We also checked public blacklists, but found no significant issues with several popular URL shortening services.

However, the experience was a reminder that your email reputation -- a crucial deliverability factor -- is based on the reputation of every domain that’s included in the messages you send.

"Any time you use link to a domain outside of your control, you take on a deliverability risk," says Al Iverson, Director Privacy and Deliverability, Exact Target. "Other uses of that domain by other folks could have caused a reputation issue that will now impact you."

There has been an explosion URL shortening services, such as TinyURL, Bit.ly, Tr.im, Cli.gs, and dozens more. The growing integration between email marketing and social media channels that depend on short URLs, such as Twitter, means it’s becoming more common for email messages to contain these kinds of links.

With that in mind, we wanted to remind marketers of the impact third-party links can have on deliverability. Here are four tips for checking whether the URLs include in your messages -- whether shortened or long-form -- might hurt your reputation:

Tip #1. Check link domains against blacklists

Although we found no major ban on short URL services, that doesn’t mean that isolated problems can’t arise. Every spam filter is different, and even a temporary addition of a domain on a certain blacklist can get your messages blocked if you include a link from that domain before the situation is resolved.

"ISPs whitelist major domains, but if you have a new player come on to the scene and the filters haven’t been updated yet, I can see [problems] happening," says Laura Villevieille, Senior Deliverability Consultant, Lyris.

Even if you’ve used a link from a specific domain with no previous problems, you should always check the reputation of the links in your messages.

- Many ESPs include a spam checking feature that will assess the contents of your message before you send.

- You also can check links against public blacklists through several online resources. (See Useful Links section, below, for a few blacklist-checking services.)

Tip #2. Send test messages to seed addresses

Before sending a message to your list, use the seed addresses you have set up with major email domains such as Gmail, Yahoo!, MSN, and AOL.

Send a test email with and without the third-party link to see if its inclusion causes deliverability problems.

Len Shneyder of Pivotal Veracity also suggests sending a test email that only contains the third-party link and seeing if it is blocked. That test can tell you whether the problem is being caused by the link itself, or by some combination of the link and your other email content.

Tip #3. Use a custom URL shortening service

If you frequently include short URLs in your email messages and are concerned about a third-party domain’s reputation influencing your own, you can create you own short URL service. These custom short links will feature the same URL -- and reputation -- as the domain from which you’re mailing.

You can work with your own IT department to create a homegrown URL shortening code. Or, you can find third-party services that provide custom short URL codes based on your own domain. Custom short-link providers include:
o BudURL
o Awe.sm

Josh Baer, CEO, OtherInbox, uses a URL-shortening feature provided by Google Apps, which powers his company’s email messaging. That feature lets Baer’s team create custom short links, such as "go.oib.com"

"Today, that’s the ultimate solution -- create your own short URL domain," says Baer. "From a deliverability standpoint, you’re better off if all the links in an email match the URL you’re sending from."

Tip #4. Keep your overall email reputation high

The best defense against delivery problems is maintaining an excellent email reputation. Even as you pay attention to the links you’re including in your messages, stay focused on all the other factors that influence your reputation.

Besides message content, major contributors to your email reputation include:

- List quality and hygiene

Sample action: Regularly clean your list to eliminate hard bounces, un-recovered soft bounces, typos, etc.

- Complaint rate

Sample action: Review your opt-in procedure to make sure subscribers understand your intentions, and process unsubscribe requests quickly to reduce complaints.

- Identity consistency

Sample action: Avoid changing your IP address.

- Transmission rate, volume and frequency

Sample action: Avoid sudden spikes in message volume, which can be interpreted as spam blasts.

- CAN-SPAM compliance

Sample action: Make it easy for subscribers to use your opt-out link.

Useful links related to this article:

Check Your Email Reputation to Improve Deliverability with Easy, No-Cost Tools
http://www.marketingsherpa.com/article.php?ident=31046

Deliverability Cheat Sheet - 27 Action Points to Fix Your Email Reputation Now
http://www.marketingsherpa.com/article.php?ident=30114

Blacklist research tools:

MXToolBox
http://www.mxtoolbox.com/blacklists.aspx

SpamAssassin Rules Emporium
http://www.rulesemporium.com/cgi-bin/uribl.cgi

SmamCop
http://www.spamcop.net/bl.shtml

Custom-domain URL Shortening services:

Awe.sm
http://totally.awe.sm/

BudURL
http://budurl.com/

Google Apps
http://www.google.com/apps/intl/en/business/index.html

Other companies mentioned in this article:

Exact Target
http://email.exacttarget.com/

Lyris
http://www.lyris.com/

OtherInbox
http://otherinbox.com/

Pivotal Veracity
http://www.pivotalveracity.com/