It is necessary to set up two DNS records so that system emails come from your own domain:
If you already use a SPF TXT Record, insert the following:
This should be inserted before the last operator (?all)
If you do not already have a SPF Record, create a TXT containing at least the following values:
v=spf1 include:spf.mandrillapp.com ?all
Create a new TXT Record with the name mandrill._domainkey.yourdomain.com and replace yourdomain.com with your domain address.
Enter one of the following options as the value. There are two options because the value contains semicolons and DNS servers can react differently.
v=DKIM1\; k=rsa\; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrLHiExVd55zd/IQ/J/mRwSRMAocV/hMB3jXwaHH36d9NaVynQFYV8NaWi69c1veUtRzGt7yAioXqLj7Z4TeEUoOLgrKsn8YnckGs9i3B3tVFB+Ch/4mPhXWiNfNdynHWBcPcbJ8kjEQ2U8y78dHZj1YeRXXVvWob2OaKynO8/lQIDAQAB\;
v=DKIM1; k=rsa; p=MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCrLHiExVd55zd/IQ/J/mRwSRMAocV/hMB3jXwaHH36d9NaVynQFYV8NaWi69c1veUtRzGt7yAioXqLj7Z4TeEUoOLgrKsn8YnckGs9i3B3tVFB+Ch/4mPhXWiNfNdynHWBcPcbJ8kjEQ2U8y78dHZj1YeRXXVvWob2OaKynO8/lQIDAQAB;
Most DNS providers offer a control panel to explain the settings in more detail.
If you experience difficulties, please refer to your DNS provider customer service for help.