Write emails that land in the inbox
How the words, links and formatting of a cold email affect spam filtering, and what OmniLead's compliance checker looks for.
Authentication and sending limits get your email to the recipient's server. What happens next depends partly on the email itself. Spam filters read the subject, the body, the links and the formatting, and they learn from how recipients react. This page covers the parts you control when you write.
Write like a person
The emails that land are the ones that look like a person wrote them to one other person:
- Plain text or near-plain. No banner images, no heavy HTML layouts, no colored buttons.
- Short. Under 120 words for a first email. Follow-ups can be two or three sentences.
- One clear ask. A question they can answer in one line, such as "Is this something you're looking at this quarter?"
- Specific. One sentence about why you're writing to them in particular: their fund's thesis, their recent paper, the problem their team posted about.
A relevant email gets replies, and replies are the strongest positive signal a mailbox provider sees.
Subject lines
- Keep it short and honest. It should describe the email.
- Avoid all caps, strings of punctuation (
!!!,???) and currency symbols. - Never fake a reply or forward with "Re:" or "Fwd:" on a first email. It's deceptive, and it's illegal under CAN-SPAM.
- Test variants with A/B testing rather than guessing.
Spam-filter phrases
Some phrases appear far more often in spam than in real email, and filters weigh them. OmniLead's compliance checker flags common ones, such as "risk-free", "100% free", "guaranteed", "no obligation" and "click here".
You don't have to avoid every word on a list. Rewrite the sentence in plain language instead:
Links
- One or two links in a first email. The unsubscribe link in the footer doesn't count against you.
- Use your own domain where you can. Link shorteners are heavily abused and often filtered.
- Show where a link goes. Descriptive text or a clean URL, not "here".
- No attachments in a first email. Link to a deck instead, or offer to send it.
OmniLead's compliance checker warns at three or four links and fails at five or more.
Tracking
Open tracking adds an invisible image to every email. Many filters treat tracking pixels as a mild negative signal, and many mail apps block or pre-load them, so open rates are unreliable anyway. OmniLead leaves open tracking off by default. Measure replies instead.
Personalization that helps
Merge tags help when they make an email more relevant, not when they only make it look personal.
- Use fallbacks, such as
{{firstName|there}}, so no one gets "Hi ,". See Merge tags reference. - Vary your opening line. Hundreds of identical emails with only the name changed are easy for filters to spot.
- Use a custom field for a real detail, such as the investor's focus or the researcher's latest paper.
The footer
Every OmniLead email ends with your postal address and an unsubscribe link. They're legally required in most places, and they help deliverability: a clear way to opt out means fewer people press Report spam, and spam complaints hurt far more than unsubscribes.
Check a draft before you send
The compliance checker in the sequence editor reviews each email step and marks every check as pass, warning or fail, with a link to the relevant doc:
- Postal address and unsubscribe link present
- Honest subject line and a clear sender identity
- No pressure or urgency tactics
- Spam-filter phrases
- Number of links
Fix failures before launch. Warnings are judgment calls: read them, and decide.