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'.

A late-sequence email explicitly inviting subscribers to unsubscribe may seem counterproductive, but it acts as a powerful filter. Those who remain are more invested, leading to higher long-term engagement and fewer spam complaints. This weeds out subscribers who would have disengaged later anyway.

Email providers track engagement. When many subscribers ignore your emails, algorithms assume your content is low-priority, filtering it to spam or promotions for everyone—even your most loyal followers. A clean list improves deliverability for your entire audience.

Automatically enrolling your entire list into a high-frequency email series (opt-out) instead of requiring an explicit opt-in harms engagement. Subscribers who actively opt-in are more excited about the content and significantly more likely to share it, leading to better referral growth.

Be cautious with the "resend to unopens" feature. Tests show it often fails to meaningfully increase overall open rates. Worse, it can annoy subscribers and lead to spam complaints, especially since open-tracking pixels are not foolproof and may misidentify readers as non-openers.

Getting a subscriber to reply to a marketing email is the number one signal to inbox providers that your content is valued. This single action dramatically improves future email deliverability and keeps your campaigns in the primary inbox.

Don't fear unsubscribes. If no one is leaving your email list, your content is likely too generic and not pushing boundaries. Having people opt-out is a healthy sign that you are polarizing enough to attract a dedicated following while repelling those who aren't a good fit for your brand.

An unsubscribe indicates that a recipient opened and clicked your email, which are positive engagement signals for email providers. Making it difficult for users to unsubscribe is more harmful, as frustrated recipients will mark your email as spam, which severely damages your sender reputation.

Tracking pixels used for open rates harm email deliverability and can get your domain flagged as spam. While useful for marketing A/B tests, sales teams focused on getting replies should disable tracking entirely. This maximizes the chance of landing in the primary inbox and appears more authentic to both filters and recipients.