Messaging URL best practices

Oftentimes, bad actors are using common URL shorteners to mask the true nature of their campaigns. As a result, we’re seeing an increasing trend in the messaging industry where messages that use common, publicly available URL shorteners get blocked. In this article, we’ll discuss the best practices for using URLs to maximize the deliverability of your messages.

Common disallowed URL shorteners

• bc.vc
• bit.ly
• budurl.com
• clicky.me
• goo.gl (Google Drive links are also disallowed)
• Is.gd
• lc.chat
• s2r.co
• soo.gd
• tiny.cc
• tinyurl.com

Note: “Premium” or “paid-for” versions of these URL shorteners are also disallowed.

What type of URL should I use to maximize deliverability?

Although this may not make sense for every business, we’ve seen successful delivery using the full URL. If using a URL shortener, we strongly recommend using a proprietary one. It's a best practice to include "https://" to signify the link is secure within a message. The URL shortener should be unique to each business to make it clear to consumers what the content is and where they’re being directed to. 

For example, if the URL shortener https://bndw.com is used for Raleigh Day Spa and Joe’s Pizza Shack, the campaigns are at a higher risk of flagging a filter because the same URL is being used across different campaigns/brands. Those filters are set to block traffic that mimics SPAM patterns that bad actors typically use. We have no control over downstream blocks that happen outside the Bandwidth network. However, once we confirm that the campaign details match the blocked message content, we can advocate for having the block removed on your behalf.

Note: Since all messages are subject to blocking, no particular URL(s) is guaranteed to make it through the carrier filters. As long as you follow the best practices and avoid disallowed URL shorteners, you should be able to maximize deliverability.

Can my messages still encounter a block if I use a proprietary URL shortener?

Yes, all messages being sent through the messaging ecosystem are subject to blocking at any level. Bandwidth customers will typically receive error code 770/750 for SPAM. If you encounter a spam block, please open a ticket with the Bandwidth Deliverability Team to investigate. To help speed up the investigation, make sure to provide message samples (from, to, and timestamp), content, and campaign/verification ID.

Why are my messages with a URL shortener getting delivered successfully to one carrier but are getting blocked by another?

Messaging channels are not regulated by the Federal Communications Commission (FCC).  Therefore, carrier networks are considered private, meaning they can make their own policies and compliance requirements for traffic running over their private networks. For example, AT&T has advised they won’t accept any traffic containing a URL shortener even if it’s proprietary.  

It's possible that if a block happened downstream (with our partner or at the carrier level), the carrier could choose to keep the blocking event enforced until their requests for additional information are satisfied.

What measures has Bandwidth taken to mitigate shortened URL fraud?

Bandwidth has implemented additional security measures to block messages that contain shortened URLs. These more stringent filters will ensure that we’re aligned with the current industry standards and help strengthen consumer protections against SPAM. With this change, you may see an increase in messaging errors, specifically 4470 error codes.