Best Email Deliverability Services & Tools (2025 Guide)

Delivery is the technical success of sending an email to a receiving server without it bouncing. A 99% delivery rate means 99% of your emails were accepted. Deliverability refers to where that email ends up after being accepted—the primary inbox, the promotions tab, or the spam folder. High deliverability means you're reaching the inbox.

They use complex algorithms that analyze hundreds of signals, including: your sender reputation (domain and IP), whether you have proper SPF/DKIM/DMARC authentication, the content of your email (spammy words, misleading links), and most importantly, how users engage with your emails (opens, clicks, spam complaints).

Often, yes. A common and effective "stack" includes: - An Email Sending Provider (ESP): Like SendGrid or Postmark for sending emails. - An Email Validation Service: Like VitaMail to clean your lists before you send. - An Inbox Placement Tester: Like GlockApps to diagnose issues and test campaigns.

SPF: A list of approved senders for your domain. (Who can send?) DKIM: A digital seal proving the email is authentic and unaltered. (Is it really you?) DMARC: The rules for what to do if the SPF or DKIM checks fail. (What happens if it's fake?)

You can use free online tools like MxToolbox. You enter your domain or sending IP address, and it will check it against dozens of common blacklists. If you are listed, the tool will often provide a link to the blacklist's website with information on how to request delisting.

Fixing authentication involves adding or correcting DNS records (TXT records) in your domain registrar's settings (like GoDaddy, Namecheap, etc.). Your email service provider will give you the exact values to copy and paste for your SPF and DKIM records. Setting up DMARC involves creating another TXT record with your desired policy. If you're not comfortable with DNS settings, it's best to ask a developer or your IT department for help.