Dedicated IPs

By default your mail leaves from usend's shared infrastructure, with reputation shared in the IP pool that usend manages and monitors. A dedicated IP is one that only your organization uses, so its reputation depends only on you.

#How sending works on usend

usend sends from its own relay IPs (reached through the edge relay) or, for some organizations, through Amazon SES. The usend team chooses the route for each organization. Within the relay route, an organization either uses the shared pool of relay IPs, or is pinned to one dedicated relay.

#Do you need one?

Probably not at first. A dedicated IP helps when:

• You send high, steady volume (hundreds of thousands per month or more). Low volume does not build a reputation of its own.
• You must isolate your reputation from other customers.
• You need to allow-list a stable sending IP with a partner, or register the IP with a provider's tools.

A dedicated IP does not fix a bad list. It also makes your reputation entirely yours: good or bad. And it needs warming.

#Availability

Dedicated IPs come with the Scale plan and Enterprise plans (see Plans and limits). They are assigned by the usend team: you cannot switch yourself. Write to [email protected] with your expected volume and what kind of mail you send.

#What changes

• Warm-up. A new IP starts with no reputation and ramps up from scratch, with a daily cap that grows over time. Plan to send your most engaged mail first and expect the first weeks to be slower: Warm up a domain. Excess volume waits and is sent on the following days.
• SPF and DNS. The sending IP must be covered by the SPF record behind your return path, and it needs reverse DNS (PTR). usend takes care of both on its side; your return-path CNAME stays as it is.
• No fallback. If your organization is pinned to a dedicated relay, mail goes only through that relay and never spills over to the shared pool. If it is unreachable, sends are retried and fail after the retries are used up, instead of leaving from another IP.
• Your domain's reputation still matters. Domain reputation (DKIM, From domain) is separate from the IP and stays with you.

#Keep it healthy

The same rules apply: low bounces and complaints, confirmed lists, steady volumes. See Audience hygiene and Why emails go to spam.