Using subject lines like "Verify your active status" can lift open rates by 27-31% for contacts who haven't engaged in over a year. While effective for reactivation, this slightly gimmicky approach will also annoy some users, leading to a higher-than-usual unsubscribe rate and negative replies, which requires 'thick skin'.

From Nov 20th to Dec 20th, sending a personal letter-style email from a founder or executive to unengaged contacts can increase open rates by 40%. The key is changing the "from name" to a person, not the brand, and using a subject line that acknowledges their absence. This strategy works for both B2B and B2C brands.

To test if subscribers are actually reading your full email, hide a specific, fun instruction in the middle of the copy (e.g., "If you see this, reply with this word"). The replies you receive serve as a clear indicator of deep engagement beyond just opens or clicks.

Email providers prioritize senders with high engagement. Sending at least five emails per month generates more opens and clicks, signaling credibility. This counterintuitively leads to higher average open rates and better inbox placement, contrary to the common fear of over-sending.

A sudden increase in unsubscribes after a marketing change isn't necessarily a failure. It often means you've successfully grabbed the attention of disengaged subscribers who then self-select out because the content is no longer relevant, which is a healthy outcome for your list.

Prompting subscribers with simple, non-work-related questions (e.g., "What's your favorite holiday cookie?") encourages replies. This builds a conversational relationship, improves engagement signals, and positively impacts email deliverability and open rates.

The holiday season sees a massive spike in email unsubscribes. This isn't due to your marketing efforts, but because people are trying to "clean up" their inboxes for the new year. Marketers should anticipate this trend and not misinterpret it as a sign of poor campaign performance or reduce email frequency.

Shift your primary success metric from passive opens to active replies. A reply signifies a genuine two-way conversation and a much deeper level of engagement. Actively inviting responses in your emails transforms a broadcast into a powerful relationship-building tool and provides invaluable audience feedback.

For subscribers who don't open an email, a simple and effective tactic is to resend the exact same content. The only change is tweaking the subject line and pre-header to capture their attention. Since they never saw the original content, it's still new to them and requires minimal effort to redeploy.