Lock Down Your Mail Server
Following best security practices, you should lock down your email server to only accept email from Email Protection. Leaving it open to accept email from other sources leaves your mail server exposed to an attack and limits Email Protection's effectiveness.
If you are an Office 365 customer, see Locking Down Your Office 365 Mail Server.
From the table below, select the corresponding IPs on the same row as your Email Protection login URL. Then, set up your email server to only accept mail from those IPs.
Email Protection Servers
There are a number of Email Protection servers, one of which your account is on. Find your login URL in the table below to see the corresponding MX and IPs to use during setup.
Region: US (Ohio, USA)
| Section | Host Name | IP Address |
| Portal | https://smtp-ui.emailprotection.us.xcitium.com | 3.162.103.8 3.162.103.13 3.162.103.116 |
| API URL | smtp-api.emailprotection.us.xcitium.com | 3.18.72.123 |
| MX1 | smtp1.emailprotection.us.xcitium.com | 52.14.97.38 3.19.220.157 |
| MX2 | smtp2.emailprotection.us.xcitium.com | 3.133.191.51 18.188.162.249 |
Region: EU (Frankfurt, Germany)
| Section | Host Name | IP Address |
| Portal | https://smtp-ui.emailprotection.eu.xcitium.com | 99.84.108.28 99.84.108.47 99.84.108.82 99.84.108.99 |
| API URL | smtp-api.emailprotection.eu.xcitium.com | 3.64.91.80 |
| MX1 | smtp1.emailprotection.eu.xcitium.com |
3.72.208.216 |
| MX2 | smtp2.emailprotection.eu.xcitium.com | 3.65.85.30 |