Many mail servers do not do enough in spam prevention technology, resulting in users' mailboxes being crawled by spam. They spend a lot of energy to deal with spam every day, which not only takes up normal working hours, but also may affect their daily work because of the omission and accidental deletion of important emails.
In addition, it may be that foreign mail is not sent and received well. Nowadays, many enterprises often use e-mail for business communication, especially export-oriented enterprises that have trade with overseas enterprises. E-mail is an important guarantee for their business development. However, due to the generally low reputation of domestic mail IP, it is easy to be intercepted by overseas mail servers, enter garbage bins or be blacklisted directly, which hinders the normal information exchange between enterprises. There are only many cases in which orders of foreign companies are lost because of mail delivery problems.