Deliverability best practices

Deliverability is the work of reaching the inbox instead of the spam folder. It rests on your sending domain's reputation with each mailbox provider, on the quality of your list, and on your content. Sendara authenticates your domain and suppresses bad addresses for you. The rest is in your hands. This page collects the practices that matter most, in rough order of impact.

1. Authenticate every sending domain

Publish the 6 DNS records that Sendara returns when you add a domain, so DKIM, SPF, and DMARC all verify. Google and Yahoo now refuse or spam-folder bulk mail that is not authenticated. Sendara generates the records, including a starter DMARC record at p=none, and checks them after you publish them. See Domains and deliverability.

2. Raise your volume in stages

A new domain has no sending history, so a mailbox provider has no reason to trust it yet. If you send a large volume from a cold domain on the first day, Google and other providers throttle the mail or route it to spam, and that early reputation is hard to undo.

Sendara sends through shared Amazon SES infrastructure and does not raise your volume for you. Build the history yourself:

• Start small. Send a few hundred messages a day to your most engaged recipients first, meaning people who opened or replied recently.
• Raise the volume in stages over two to four weeks rather than all at once. Roughly doubling every few days is a common pace.
• Watch your bounce rate and complaint rate at each step. If a rate climbs, hold the volume until it settles.
• Keep a steady daily pattern. A large spike after a long gap reads as suspicious to a mailbox provider.

3. Meet the Google and Yahoo bulk sender rules

Google and Yahoo require anyone who sends about 5,000 messages a day or more to their consumer inboxes to meet a fixed set of rules. Sendara covers part of this for you:

• Authenticate with SPF, DKIM, and DMARC. Sendara generates all three records for you.
• Add a one-click unsubscribe to marketing mail. Sendara adds the RFC 8058 List-Unsubscribe header and a visible footer link to every marketing send, so this is handled.
• Keep the spam complaint rate below 0.3%. Google states 0.3% as the maximum and recommends that you stay under 0.1%. This one depends on who you send to, so it is on you.

4. Keep complaints and bounces low

Complaints and bounces are the fastest way to lose a domain's reputation.

• Send only to people who asked for your mail. Purchased and scraped lists are the single most common cause of a ruined domain.
• Sendara suppresses an address after a hard bounce or a complaint, and it refuses later sends to that address, so you never mail a known-bad recipient twice.
• Sendara marks your account health from these rates. A complaint rate above 0.1% sets the health to critical. A bounce rate above 5%, or above 2%, sets it to warning. Read both on the analytics endpoints, and stop to clean the list when a rate crosses a threshold.

5. Watch how Gmail rates your domain

Register your domain with Google at postmaster.google.comto see your domain's reputation, your spam complaint rate, and your authentication results as Gmail measures them. Read your DMARC aggregate reports for the same view across providers. Sendara reports the delivery, bounce, and complaint events that Amazon SES returns, and it does not measure which folder holds a message.

6. Separate your transactional and marketing streams

Put transactional mail (receipts, password resets, alerts) on one subdomain such as mail.acme.com, and marketing mail (campaigns, newsletters) on another such as news.acme.com. A complaint against a campaign then does not drag down the reputation your receipts depend on. Sendara registers each subdomain as its own SES identity, with its own DKIM keys. See Domains and deliverability.