If customers tell you your quotes went to their junk folder, the cause is almost always that your domain has not told the world who is allowed to send mail for it. Google, Microsoft and the rest now require three DNS records before they trust a sender, and a surprising number of small businesses are missing at least one.
The three records
SPF is a list of servers allowed to send mail as your domain. If your website host, Microsoft 365 and your invoicing tool all send email as you, all three need to be in it. One text record on the domain.
DKIM is a signature. Your mail server signs each message with a private key; the public half sits in DNS so receivers can check nothing was altered. Your email provider gives you the record to add.
DMARC tells receivers what to do when a message fails the first two checks (let it through, quarantine it, or reject it) and where to send reports. Start at p=none to see what is sending as you, then move to p=quarantine, then p=reject.
Why it matters now
Since 2024, Gmail and Yahoo reject or junk bulk mail from domains without these records, and Microsoft followed. The threshold for "bulk" is lower than people think. More importantly, without DMARC anyone can send email that looks exactly like it came from you, and your customers have no way to tell. That is how invoice fraud starts.
The fifteen-minute check
- Go to a free DMARC checker and enter your domain.
- If it says no SPF, no DKIM or no DMARC, that is the problem.
- If SPF exists but has "too many lookups", it has grown past the limit of ten and is silently failing. This is common in businesses that have changed providers a few times.
- If DMARC is at
p=noneand has been for years, nobody is reading the reports. Move to quarantine.
What we do
For clients on our hosting or on a support plan we set all three up, tighten DMARC over a few weeks while watching the reports, and add the BIMI record that lets your logo show beside your messages in supporting mail clients. It is one of the highest-value hours in the whole technology stack, and one of the least visible.
Cabling, networks, cameras, access control, smart homes, hosting and software for homes and small business across Southwestern Ontario. Twenty-plus years in the trade, and we still answer the phone.