分类归档：退信分析

550 SPF check failed

550 Domain may not exist or DNS check failed [NX9WKUWGGZoEdpKuMBJbEmXcZnp1+GoEt62NhQ65bRw2iEld1x+go68= IP: xx.xx.xx.xx]

550 5.7.1 xxx@xxx.xx may not send mail to

550 Service unavailable; Client Host [xx.xx.xx.xx] blocked using Trend Micro RBL+

550 5.7.1 Recipient unknow<…@...>