On Oct 15 2018, the old webmail IP address will be changed. This article explains if you need to update your DNS to ensure your webmail subdomain continues to function.
When you add email to your domain, DreamHost automatically creates several DNS records that control where your email is sent. You can view a list of those records on this page:
Due to DreamHost's email improvements, the IP address of the 'webmail' subdomain was recently changed.
Old webmail IP address
New webmail IP address
Depending on your site's DNS configuration, you may need to update your webmail IP address.
Do I need to change my email DNS records?
Maybe. This depends on where your site's Nameservers are pointed.
If your site's Nameservers are pointed to DreamHost, you do NOT need to adjust your email DNS records.
If your site's Nameservers are NOT pointed to DreamHost, you will need to adjust the webmail IP address at the company that hosts your Nameservers.
How do I check where my Nameservers are pointed?
You can check on a site such as this:
Enter your name into the text box. Make sure the 'Domain' radio button is selected, then search. You will see an output of your WHOIS records. You're looking for the following records:
What if my Nameservers are not pointed to DreamHost?
If your site's Nameservers are not pointed to DreamHost, you must log into your account at the company where they are pointed. From there, you'll need to adjust the following A records:
webmail. (A) 220.127.116.11 www.webmail. (A) 18.104.22.168
If you need assistance on updating those IP addresses, you'll need to contact the company where your Nameservers are pointed.