What Mailchimp does to make sure emails get delivered
I run a number of mail servers -- my own (for myself, friends, and family) and for my employer (an ISP&#x2F;hosting provider) and just wanted to mention something.<p>If you are sending out &quot;legitimate&quot; bulk mail, one of the best things I think you could do is use one of these E-mail Service Providers that will use a dedicated IP address for your email.  That is, all mail you -- and only you -- send via Mailchimp&#x2F;SES&#x2F;etc. will always be sent from IP address <i>a.b.c.d</i>.<p>Everyday, I see many IP&#x27;s belonging to these ESPs that end up blacklisted (either on public blacklists or our own, internal, automated blacklists).  If you&#x27;re using a service that sends out mail from multiple customers from a &quot;shared&quot; IP address, you <i>WILL</i> have delivery problems <i>WHEN</i> (not <i>if</i>) that IP address gets blacklisted or flagged.<p>I&#x27;ve managed and ran my own servers for years, including mail servers.  I&#x27;ve never ran into any issues that so many others seem to when doing this, but I always make sure that I follow best practices and do things The Right Way(TM).  This includes, nowadays, SPF, DKIM, DMARC, DNSWL, and so on.<p>We&#x27;re fairly small and yet I can detect and put a stop to &quot;spam outbreaks&quot; quickly when they happen (such as when an e-mail user responds to a phishing e-mail, gives out their credentials, and their account is hijacked to send out spam), so these other providers (especially those who provide&#x2F;specialize in e-mail services) certainly should be able to as well.