Email marketing is an integral component of any marketing campaign, yet many marketers struggle to optimize their brands’ potential through this channel. Are your messages getting stuck in the spam folder? Watch out for these email marketing red flags:

Red flag #1: Your “hard bounce” rate is greater than 1%.

A “bounce” occurs when an email fails to reach the intended recipient. Unlike a “soft bounce” which means a recipient is temporarily unavailable (e.g., vacation auto-responder or full mailbox), a “hard bounce” means that the message is permanently undeliverable. An invalid email address is the primary cause for hard bounces.

The industry standard bounce rate hovers around 1%, according to an analysis of email marketing campaigns performed by MailChimp. This rate varies between industries; non-profits are on the lower end (0.7%) while manufacturing businesses are on the higher end (1.9%). If your email marketing hard bounce rate is greater than 1%, this is a red flag that your email address list is stale. Fix this mistake: Keep your list “fresh” by checking in with subscribers. Every quarter, send a “check-in”email confirming that subscribers wish to continue receiving messages from your company and that you have their correct email address.

Red flag #2: Your click-thru-rate is lower than 2%

The average email click-thru-rate (CTR) hovers between 2 and 5%, according to MailChimp. And while this figure may be slightly lower or higher depending on your industry, a CTR less than 2% is a sure-fire sign that your current email marketing strategy is failing. And even if your CTR is on par with the industry standard, why settle for average?

Lack of list segmentation is a primary cause for low CTR. List segmentation is the process of creating targeted email campaigns based on customer/client preferences and past interactions.

Fix this mistake: Start segmenting your lists from the first point of contact, such as a web sign-up form. Automated marketing software is key to tracking client/customer interaction touch points, including both the frequency of communication as well as the communication’s content.

Red flag #3: Your email is not optimized for smartphone viewing.

Optimizing your email for smartphone viewing is more than simply selecting the right format for graphics and text layout. From subject line length to call-to-action, content must also be optimized for smartphones.

Fix this mistake: Get to the point. Subject lines should be between 35 to 50 characters, body content should be no longer than one or two short paragraphs, and your email should end with a clear call-to-action (CTA). Use design to make your hyperlinks stand out and visually direct your reader to the call-to-action. Whenever possible, localize and personalize.