> ## Documentation Index > Fetch the complete documentation index at: https://docs.brudcast.com/llms.txt > Use this file to discover all available pages before exploring further. # Deliverability overview > What decides whether your email is accepted and reaches the inbox, and the guardrails Brudcast enforces on every send. Deliverability is whether your email is accepted by the receiving server and, beyond that, whether it lands in the inbox rather than spam. Nobody can guarantee inbox placement. What you can do is send mail that receivers trust, and Brudcast helps by enforcing a set of guardrails on every send. ## What receivers look at Mailbox providers such as Gmail, Yahoo and Outlook decide where a message goes based on: * **Authentication.** Does the message prove it really comes from your domain? See [Authentication explained](/deliverability/authentication-explained). * **Reputation.** How have people reacted to mail from your domain and your sending servers before? Spam complaints and bounces hurt it; opens and replies help. * **Consent and relevance.** Did the recipient ask for this, and do they engage with it? * **Volume patterns.** A sudden jump in volume from a new sender looks like spam, even when it isn't. ## Why Brudcast has guardrails Unless you have [dedicated IPs](/deliverability/best-practices#dedicated-ips), your mail leaves from servers shared with other Brudcast customers. One sender's spam can hurt everyone's delivery on those servers. The guardrails below exist so that doesn't happen, and so a problem on your account is caught while it's still small. ```mermaid theme={"system"} flowchart LR A["Your send"] --> B["Sending review"] B --> C["Sending limits"] C --> D["Suppression list"] D --> E["Signed and sent"] E --> F["Reputation checks"] F -. "high complaints or bounces" .-> C ``` ## The guardrails | Guardrail | What it does | When it applies | | --------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------- | | [New-account sending limits](/deliverability/new-account-sending-limits) | Caps how much email you can send per day, rising over your first 30 days | Every organization | | [Sending reviews](/deliverability/new-account-sending-limits#sending-reviews) | Pauses an unusual send until a person at Brudcast checks it | Large first sends, sudden volume jumps, large early imports, complaint spikes | | [Suppression list](/deliverability/bounces-complaints-and-suppression) | Stops mail to addresses that bounced, complained or unsubscribed | Every email, from campaigns, the API and SMTP | | [Reputation and suspension](/deliverability/reputation-and-suspension) | Warns about, then suspends, a domain or organization with high complaint or bounce rates | Every 15 minutes, over the last 24 hours | | [Unsubscribe handling](/deliverability/bounces-complaints-and-suppression#unsubscribes) | Adds a footer link and one-click unsubscribe to campaign email | Every campaign email | | [Blacklist checks](/deliverability/reputation-and-suspension#blacklist-checks) | Checks your verified domains against domain blacklists | Once a day | ## What's up to you Brudcast can stop the worst outcomes, but your own habits decide your reputation: 1. Only email people who asked to hear from you. 2. [Authenticate your domain](/channels/email/add-a-sending-domain) and send from it, not only from the Brudcast trial address. 3. Grow volume gradually. 4. Watch **Reports > Deliverability** after every large send. The [best practices](/deliverability/best-practices) page covers each of these in detail. ## Related SPF, DKIM and DMARC in plain language. How your daily limit grows over 30 days. Why an address stops receiving your mail. The rates that warn or suspend a domain, and how to recover. Habits that keep your mail in the inbox.