The pre-header, or second subject line, critically impacts opens. Using specific continuation words like "and," "but," or "plus" at the beginning of the pre-header compels the reader to continue from the subject line, which can lift open rates by a significant margin.

A rarely used but effective tactic is placing the same emoji at the beginning and end of the email preheader (the second subject line). This visual framing technique draws attention in a crowded inbox and can improve open rates for both B2B and B2C campaigns.

While many marketers use brackets at the beginning of email subject lines, new data from subjectline.com shows placing them at the end is boosting open rates. This tactic works by drawing the reader's eye to a key callout, and contrary to myth, it does not negatively impact deliverability or land emails in spam.

To maximize open rates, craft short (1-4 word) subject lines that mimic internal emails. This means using all lowercase or sentence case capitalization. Critically, avoid elements that scream "sales email," such as questions, numbers (e.g., "10x"), and even customer name-dropping, which hurts opens despite being effective in the email body.

To stand out from polished, AI-generated emails, use unconventional formatting. Tactics like extremely long subject lines, starting with an ellipsis, or using all lowercase letters grab attention by looking distinctly human and breaking patterns.

In a crowded inbox, create visual disruption by using a very short subject line (e.g., three words) and intentionally leaving the preheader blank. This generates significant white space around your email, making it stand out from the 98% of messages that have preheaders and boosting open rates.

The pre-header, or second subject line, has a major impact on open rates. Using continuation words like "and," "but," or "plus" at the beginning of the pre-header encourages the reader to continue from the subject line, which can result in a significant open rate lift of up to 10%.

Many marketers mistakenly reveal the entire value of an email in the subject line, killing any reason to open it. To maximize opens, provide a compelling hint or create a curiosity gap rather than giving away the full story.

To differentiate from grammatically perfect, AI-generated emails, use unconventional tactics. Starting subject lines with ellipses or using all lowercase letters violates normal rules, which makes the email feel more human and captures attention, lifting open rates by as much as 15%.