Steer clear of employing overly aggressive subject line formatting, which encompasses:

• Excessive use of capital letters
• Over-reliance on exclamation and question marks
• Generic marketing phrases
• An abundance of emojis

These tactics do not lead to higher open rates; rather, they make your emails appear overly promotional and distant.^[1]  Such formatting can also give off an impression of being of lower quality and may erode user trust.

Moreover, research from the Nielsen Norman Group indicates that incorporating emojis into subject lines can lead to a 26% increase in negative perceptions. Users frequently describe such emails as "boring," "dull," and "frustrating" when compared to emails that refrain from excessive emoji use.^[2]