You send a campaign to 4,800 people. The dashboard says they were delivered. You CC yourself and two coworkers, and they can't find it. Did it arrive or not?
Almost always, it did. What you don't know is which folder it landed in. An email goes through three stages, and only the first two can be measured.
Sent, delivered, and in the inbox
- Sent: your email provider accepted the message and put it on its way.
- Delivered: the recipient's server (Gmail, Outlook, their company's) accepted it. If it doesn't, the email bounces and you see it as bounced.
- In the inbox: the server decides whether it goes to Primary, Promotions or Spam. Nobody reports this back to you.
In Boom you see the first two for every email in the message logs. An address that bounces permanently, or that marks your email as spam, stops receiving emails on its own, so it doesn't hurt your reputation.
For the third stage, your best clue is opens. If a group of people receives everything but almost never opens, your emails are probably landing in their Spam or Promotions.
1. Serve your images from your own domain
This is the most common mistake and the easiest to fix. Your emails come from yourbrand.com, but the logo loads from a free app host (something.vercel.app, something.netlify.app) and the photo from Google Drive (googleusercontent.com). Phishing uses those same domains a lot, so Gmail and company filters trust them less.
The fix: a subdomain of your own for images, for example assets.yourbrand.com.
- If your images already live on Vercel, Netlify or similar, add your own domain to the project and create the
CNAMEit asks for. It takes about 15 minutes. - For images on Google Drive, download them and upload them there too. Drive links also break when someone changes the file's permissions.
- Then update the URLs in your templates and send a test.
2. Make your links carry your brand too
Filters compare the sender's domain with the domains of the links in the email. An email from yourbrand.com full of links to other domains looks suspicious.
In Boom, turn on click tracking in Settings › Email › Domain and DNS, with your own subdomain (for example links.yourbrand.com). Every link goes out rewritten with your domain, and you also see who clicked.
3. Don't test only with your own domain
If you send a campaign "from" ana@yourbrand.com and test it in yourbrand.com mailboxes, you're in the worst case. Your company's server sees an email that claims to come from a coworker but arrives from an outside server, and that looks a lot like spoofing.
- Test with personal accounts: one Gmail and one Outlook. That's what your customers see.
- If your team needs to receive the campaigns, ask whoever runs your company's email to allow your sending server.
4. Watch the content
- Avoid subject lines that read as pure promotion, like "FREE" or "Last chance!!". One word won't send you to spam, but it adds up.
- More text than image. An email that's mostly one big image lands in Promotions.
- Add alt text to every image. Many mailboxes block images until the person allows them.
- Always include an unsubscribe link. Better that someone unsubscribes than marks you as spam.
How to know it worked
Make the changes, send the same campaign to a small list and compare: fewer bounces and more opens in the same mailboxes. If opens from one domain stay at zero, the problem is that server, and it's worth talking to whoever runs it.
