Terms below appear throughout guides on cold email infrastructure. Each definition is one or two sentences; follow the links in the sidebar for the full guides.
Core terms#
Cold email infrastructure
Cold email infrastructure is the set of secondary domains, mailboxes, authentication records, and sending tools used to run outbound campaigns without risking a company's primary domain.
SPF
A DNS record listing servers authorized to send for a domain. Checked against the connecting IP.
DKIM
A cryptographic signature on each message, verified with a public key in DNS.
DMARC
A policy record telling receivers what to do when SPF and DKIM fail alignment, plus reporting.
Alignment
Agreement between the visible From domain and the domain that passed SPF or DKIM.
Sender reputation
A provider's running assessment of a domain or IP based on complaints, bounces, engagement, and authentication.
Inbox placement
Share of accepted mail that lands in the inbox rather than spam.
Spam trap
An address that never opted in, used to catch senders with poor list practices.
BIMI
A DNS record pointing to a brand logo displayed next to authenticated mail; requires DMARC enforcement.
Feedback loop
A provider program that reports recipient spam complaints back to the sender.
Frequently asked questions#
How many emails can I send per mailbox per day?
Google Workspace allows 2,000, but for cold outreach 30 to 50 keeps you under behavioral thresholds.
Should I use Google Workspace or Microsoft 365 for cold email?
Both work. Workspace mailboxes tend to warm faster; Microsoft has stricter outbound spam filtering.