IP warming

When you use new IPs or domains, mailbox providers such as Gmail and Yahoo have no sending history to reference. Without this history, they can't verify whether your messages are legitimate.

Spammers commonly move between IPs and domains without warming them up (known as IP/domain hopping). To counter this, mailbox providers throttle or block messages from unfamiliar IPs and domains until they can establish trust. They may also filter messages to junk to monitor how recipients interact with them. Some filtering at this stage is normal and expected.

Best practices¶

Build a sound infrastructure¶

Apteco Email provides the DNS records (SPF and DKIM) needed to authenticate your messages. Setting up these records tells recipient servers that messages are coming from you.

You should also:

• Set up MX records for your sending domain, as some recipient servers reject messages from domains without them
• Configure a DMARC record for all sending domains to prevent malicious users from spoofing your domain

Cleanse your data¶

Before warming up, remove the following from your email lists:

• Users who have previously complained or unsubscribed
• Addresses that have hard bounced
• Inactive users

Inactive users reduce engagement metrics during warm-up. You can re-engage them later through a dedicated re-engagement campaign.

Target engaged users first¶

Send to your most engaged users first. These recipients have demonstrated that they want your messages, which signals to mailbox providers that your IP can be trusted. This approach leads to the quickest and most effective warm-up.

Start slowly¶

Follow the warming schedule below as closely as possible. If you need to go slower, that's fine. Starting too fast causes mailbox providers to filter your messages more aggressively, which creates deliverability problems that are difficult to fix.

Stay consistent¶

If you miss a day, resume where you left off rather than sending double the volume. Mailbox providers flag sudden spikes in volume as suspicious.

Don’t rush the process¶

The warm-up schedule applies regardless of how many IPs you have. Having two or more IPs does not mean you can send higher volumes from day one. Each IP builds its reputation independently.

Example warming schedule¶