My emails keep bouncing back or landing in customers' spam folders. What's wrong?

When your legitimate email bounces or silently lands in spam, the world's mail systems have decided they can't trust messages claiming to come from your domain. The usual culprits are specific: your domain's authentication records - SPF, DKIM, and DMARC - are missing or wrong, so receiving servers can't verify you are who you say you are; your sending service or its shared IP address landed on a blacklist (sometimes because of another customer on the same shared service); or your email was set up long ago in a way that modern requirements no longer accept. Google and Microsoft both tightened enforcement in recent years - configurations that worked for a decade suddenly don't.

The business impact is worse than an outage because it's invisible: an outage announces itself, while rejected mail just means quotes don't arrive, invoices go unseen, and customers think you're ignoring them. If even one customer has told you your mail bounced, assume others simply haven't mentioned it.

The good news: this is one of the most diagnosable problems in IT. A technician can read your domain's records and the actual bounce messages, identify exactly which check is failing, and usually fix it within a day - correct SPF/DKIM/DMARC records, a delisting request if you're blacklisted, or moving you off a problematic sending arrangement. If your provider shrugs at deliverability problems, that itself is a finding.