Check mail server ip

There are a few ways to check the IP address of a mail server:

MX Lookup: You can use a tool like dig or nslookup to perform an MX lookup, which will give you the IP address of the mail server. Here's an example using dig:
```
dig +short mx example.com
```
This will give you the IP address of the mail server responsible for receiving mail for the domain example.com.
Whois Lookup: You can use a whois lookup tool to find the IP address of the mail server. Here's an example using whois:
```
whois -h whois.arin.net example.com
```
This will give you information about the domain, including the IP address of the mail server.
Mail Server IP Lookup Tools: There are also online tools that can help you find the IP address of a mail server. Here are a few examples:

MX Toolbox: This tool allows you to enter a domain and get information about the mail server, including the IP address.
WhatIsMyIP: This tool allows you to enter a domain and get information about the mail server, including the IP address.
IPVoid: This tool allows you to enter a domain and get information about the mail server, including the IP address.

Check the DNS Records: You can also check the DNS records for the domain to find the IP address of the mail server. Here's an example using dig:
```
dig +short txt example.com
```
This will give you the DNS records for the domain, including the IP address of the mail server.

Note: The IP address of a mail server can change over time, so it's always a good idea to verify the IP address using multiple methods.