Deliverability

It's almost never just one thing: filters add up signals. The most common causes are domain authentication issues (misconfigured SPF, DKIM, or DMARC), low sender reputation, poor-quality lists (purchased or with many inactive contacts), suspicious content, and high bounce or complaint rates. The good news is that most of this is within your control.

Certifying your sender is the most important step for your campaigns to land. It takes two steps: verifying the email with a confirmation link, and publishing SPF and DKIM in your domain's DNS zones. Once authenticated, Gmail, Outlook, and Yahoo trust you more, and in arrobaMail, every sender shows its status with a green check.

Sender Policy Framework: a DNS record that declares which servers are authorized to send on behalf of your domain. Without a correct SPF, many providers treat your messages as suspicious.

DomainKeys Identified Mail: a cryptographic signature added to every email that verifies the content wasn't altered and that it genuinely came from your domain. Together with SPF and DMARC, it dramatically improves deliverability.

Domain-based Message Authentication, Reporting & Conformance: the policy that tells providers what to do when a message fails SPF or DKIM (reject it, mark it as spam, or just report it). It's the layer that ties the other two together and sends you reports on who's sending as you.

When you start sending from a new domain, providers watch you with distrust. Warming up means raising your volume gradually over the first few weeks to build reputation. Sending a lot all at once from a new domain is the fastest way to end up in spam.

Four actions: remove invalid addresses before sending (pre-send validation), don't reuse old inactive lists, send only to people who asked to receive your emails, and honor unsubscribes immediately. A smaller, healthy list performs better than a large, dirty one.

It's not recommended. Free mailboxes (@gmail, @hotmail, @yahoo, @outlook…) can't be certified: you can't configure SPF/DKIM on a domain you don't own, and since 2024 Gmail and Yahoo heavily penalize bulk mail sent "on behalf of" their own domains. Always use a domain of your own (for example [email protected]).

For senders at volume, since 2024 they require: full authentication (SPF, DKIM, and DMARC), one-click unsubscribe processed within ≤48 h, and keeping the complaint rate low (below 0.3%, ideally under 0.1%). arrobaMail already includes the unsubscribe link, complaint handling, and authentication so you meet these requirements.

Short, clear subject lines, no deceptive language or "trigger" words (free, urgent, excessive capitalization or punctuation). A visible unsubscribe link on every campaign. Balance text and images —never send an email that's a single image— and send only to people who gave their consent.

It's arrobaMail's own sending engine: the system that physically delivers your emails. Instead of reselling a generic SMTP, it's designed to protect your reputation with per-provider traffic shaping (Gmail, Outlook, Yahoo), automatic backoff on rejections, and gradual IP warmup. It's one of the reasons deliverability is one of our pillars.

It's an optional add-on: an SMTP server with a public IP that sends only your mail. Your reputation stops depending on how other clients behave on the shared IP — you build and maintain it yourself, and all Gmail, Outlook, and Yahoo see is your history alone. We strongly recommend it if you send regularly: plans of 100,000+ sends a month, any Unlimited plan, and reseller operations (where it also isolates each client's risk). It's not mandatory and can be added to any plan.