Warm up your SendGrid mailboxes with MailPilot
MailPilot warms up SendGrid mailboxes over SMTP for sending and IMAP for reply detection. You point MailPilot at smtp.sendgrid.net with an API key as the password, and it sends warmup mail through your SendGrid account while reading and replying on the inbox side via IMAP. This warms the sending domain and IP you've authenticated in SendGrid — critical, because SendGrid's shared IP pools mean your domain reputation is doing the heavy lifting, and a cold SendGrid domain with no history gets filtered hard.
How it works with SendGrid
Create a SendGrid API key
Generate a Mail Send API key in SendGrid and use it as the SMTP password (username is literally "apikey"). Point MailPilot at smtp.sendgrid.net on port 587.
Authenticate your domain
Complete SendGrid's domain authentication (CNAME records for DKIM). MailPilot verifies SPF/DKIM/DMARC so every warmup send is signed by your domain.
Add IMAP for replies
Provide IMAP credentials for the receiving mailbox so MailPilot can read warmup emails, reply, and rescue them from spam — the engagement half of warmup.
Ramp and monitor
MailPilot gradually increases volume to build SendGrid domain and IP reputation, then reports inbox placement so you know when to scale real sends.
Why warm up SendGrid
On SendGrid's shared IP pools you inherit the pool's baseline reputation, so your authenticated sending domain is the differentiator — warmup builds that domain's standing.
If you're on a SendGrid dedicated IP, it starts with zero reputation and must be warmed gradually or mailbox providers will throttle and spam-folder your sends.
SendGrid domain authentication (DKIM CNAMEs) has to be correct for warmup to help — MailPilot verifies it so unsigned mail never undermines your ramp.
SendGrid warmup FAQ
What credentials does MailPilot need for SendGrid? +
For sending: host smtp.sendgrid.net, port 587, username "apikey", and a SendGrid Mail Send API key as the password. For reply detection, MailPilot also needs IMAP access to the receiving mailbox so it can open and reply to warmup emails.
Does warming up SendGrid warm my IP or my domain? +
Both, depending on your plan. On shared IPs, warmup primarily builds your authenticated domain reputation; on a dedicated IP, it also warms the IP itself, which is essential before any high-volume sending.
Do I still need domain authentication in SendGrid? +
Yes — it's the foundation. Complete SendGrid's domain authentication (DKIM CNAME records) first, then MailPilot's DNS checker confirms SPF, DKIM, and DMARC are valid before warmup begins.
Warm up SendGrid the right way
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