List / Data Collection Best Practices

Best practices for List/Data collection. Opt in data is the best for success. Never buy a list.

The following guidelines are designed to help you maintain a healthy mailing list, improve inbox placement, and protect your sending reputation.

If you are unsure whether a list or contact source is acceptable, contact our support team before importing or mailing.

The Most Important Rule

Only send email to recipients who have directly opted in to receive your messages.

If a recipient did not knowingly and intentionally provide their email address to receive marketing from you, do not mail them.

Before Importing a List

When moving data from another email service provider (ESP):

• Export invalid, bounced, unsubscribed, and complaint addresses separately
• Remove hard bounced and invalid addresses before importing
• Import previously unsubscribed contacts into your Global Opt-Out List for permanent suppression
• Avoid importing contacts that have not engaged with your emails in a long time

These steps improve deliverability and reduce the risk of spam folder placement, account suspension, or damage to your sending reputation.

Start With Your Most Recent Contacts

If you are importing an older list, begin with your most recent and engaged subscribers first.

Recommended approach:

1. Import contacts who signed up within the last 12 months
2. Send to your most recently engaged recipients first
3. If results are positive, gradually import older contacts in 6-month increments
4. Consider separating contacts into different lists by signup year or engagement level

Some industries may see strong engagement from contacts older than one year, while others may not. Segmenting by signup date can help you identify problem areas more quickly.

Recommended Deliverability Benchmarks

To maintain strong deliverability and protect your domain reputation, try to stay within the following industry benchmarks:

• Hard bounce rate: Under 1%
• Spam complaint rate: Under 0.1% (fewer than 1 complaint per 1,000 emails sent)
• Unsubscribe rate: Ideally under 0.5%
• Unknown user / invalid address rate: Under 1%

Exceeding these thresholds can lead to:

• More messages landing in spam folders
• Temporary delivery blocks from mailbox providers
• Domain or IP reputation damage
• Blacklisting of your sending domain
• Deliverability issues affecting both marketing and person-to-person email

Best Practices

Recommended Actions

• Collect sign-ups through a form on your website
• Use confirmed opt-in (COI) or double opt-in forms whenever possible
• Keep records of when and where each contact signed up
• Send welcome emails immediately after signup
• Stay in contact with subscribers regularly so addresses do not become stale
• Remove invalid, bounced, or inactive contacts on a routine basis
• Segment older or less engaged subscribers into separate campaigns
• Send re-engagement campaigns before removing inactive subscribers
• Email business contacts only when there is an existing relationship and a clear expectation of communication
• Authenticate your sending domain with SPF, DKIM, and DMARC

Confirmed Opt-In Benefits

Confirmed opt-in helps:

• Verify the email address is valid
• Prevent typos and fake signups
• Reduce spam complaints
• Improve long-term engagement and deliverability
• Provide stronger proof of consent if complaints occur

Remove Inactive Contacts Regularly

Inactive contacts can hurt your sender reputation over time.

A good practice is to identify recipients who have not opened or clicked in the last 6 to 12 months and either:

• Send them a re-engagement campaign
• Move them to a less frequent mailing segment
• Remove them entirely if they remain inactive

Mailbox providers increasingly look at engagement when deciding whether to place your messages in the inbox or spam folder.

What Not To Do

Do not:

• Use purchased, rented, shared, or third-party lists
• Email contacts collected from trade shows unless they clearly opted in to receive marketing emails
• Mail to old lists that have not been used in over 12 months without warming them up carefully
• Scrape or harvest email addresses from websites
• Use LinkedIn connections, social media followers, or personal contacts unless they directly subscribed
• Mail to recipients who have already unsubscribed
• Mail to recipients who previously hard bounced
• Continue sending to contacts who never engage with your emails
• Import role-based addresses such as info@, sales@, admin@, or support@ without clear permission
• Send to contacts who were added without their knowledge through a partner, affiliate, or co-registration source

When In Doubt

If you are unsure whether a list source, signup method, or campaign strategy is compliant with best practices, contact support before mailing.

It is always better to review a questionable list before sending than to risk long-term deliverability problems.