This topic describes how to add multiple domains and domain aliases.
Domain Name:
Domain name refers to the suffix that can be selected when creating email accounts and Alibaba Mail supports the creation of multiple domain names (the multi-domain numbers are allocated according to the upper limit according to the number of accounts). If an enterprise has both domain name example.net and domain name example1.net, and the postmaster adds both of them to Alibaba Mail. Then postmaster can choose to use @example.net or @example1.net when creating email accounts. After creation, a***@example.net and a***@example1.net represent two independent email accounts.
Multi-domains are allocated proportionally based on the number of accounts as follows:
When the number of paid accounts reaches 10, the number of multi-domain subdomains is 10 by default;
When the number of paid accounts reaches 50, the number of multi-domain subdomains is 30 by default;
When the number of paid accounts reaches 500, the number of multi-domain subdomains is 100 by default.
How to Add Multiple Domains?
1. Use postmaster account login Alibaba Mail and enter domain management page> Customization> Domain Names> Domain> click Add Domain.
Note: In the screenshots, 10 paid accounts is used as an example.
2. After domain name is added, postmaster needs to set the resolution before it can be used normally. Click View How to Set and add the CNAME, MX, and TXT resolution record given in the prompt to the domain name.
3. After the resolution is added, the Status will be changed to "Verified and Available" and it can be used normally. 
How to Delete Multiple Domains?
Click the Cancel button next to the domain name to be deleted, select "I have understood the above information and agree on the cancellation of the domain name." and click OK to delete it.
After a domain has been canceled, all accounts and emails under this domain are deleted. Before you cancel the domain name, please check whether the domain name has any accounts. If you want to retain the accounts and emails, change the domain name of the accounts in advance. For more information about how to change the domain name, please check How to Edit Employee Account Information?.
How to Add the Domain Alias?
The alias of the primary domain name supports five domain aliases can be mapped to the same primary domain name. All users under the primary domain name can use the domain alias to send and receive messages. For example, if the main domain name is example.net and the bound domain alias is example1.net, then logging in to a***@example.net and a***@example1.net is actually accessing the same mailbox, and the mail sent to a***@example.net is also sent to a***@example1.net.
You can add up to five domain aliases for each domain name.
1. 1. Use postmaster account login Alibaba Mail and enter domain management page> Customization> Domain Names> Domain> click Add Alias button on the right side of the domain name to be added.
2. Enter the interface of adding domain alias, click Add Alias and fill the domain name.
3. After a domain name is added, postmaster needs to set the resolution before it can be used normally. Click View How to Set and add the CNAME, MX, and TXT resolution record given in the prompt to the domain name. After the resolution is added, the status will be changed to Verified and Available and it can be used normally.
How to Delete the Domain Alias?
Click the Cancel button next to the domain name to be deleted, and click OK to delete it. 