Definition
An allowlist (also called a safelist or approved sender list) is a collection of email addresses or domains that are explicitly permitted to send email to a recipient's inbox. Emails from allowlisted senders bypass spam filtering, ensuring they reach the Primary inbox regardless of content or sender reputation.
Allowlisting happens at multiple levels: individual recipients can add senders to their contacts or address book; email clients and mailbox providers maintain their own allowlists based on engagement and reputation; and organisations maintain domain-level allowlists for internal and trusted external senders.
Allowlist vs Blocklist
| Mechanism | Action | Purpose |
|---|---|---|
| Allowlist | Explicitly permit | Ensure trusted senders reach inbox |
| Blocklist | Explicitly block | Prevent known spammers from delivering |
| Reputation-based | Algorithmically score | Filter unknown or unverified senders |
Best Practices
- Encourage subscribers to add your from address to their contacts address book
- Ask subscribers to reply to your welcome email — replies build engagement signals
- Maintain a consistent from name and from address across all campaigns
- Apply for ISP feedback loops and postmaster programmes
- Do not rely on allowlisting as a deliverability strategy — focus on good sending practices
- For B2B, provide IT departments with your sending IPs and domains for their allowlists
Frequently Asked Questions
Yes, allowlist is the modern, more neutral term for what was traditionally called a whitelist. The term allowlist has largely replaced whitelist in the email industry to avoid racially charged language.
You cannot directly submit your domain to most mailbox providers' allowlists. Allowlisting at the provider level is earned through consistent good sending practices — low complaint rates, proper authentication, high engagement, and a strong sender reputation. Individual recipients can allowlist you by adding you to their contacts.