envelope factor

例句：

1. 1. The envelope factor is a measureof how well an email fits within thelimits of an email account.
   信封系数是衡量电子邮件是否超出电子邮件账户限制的一个指标。
2. 2. The envelope factor is also used tocalculate the cost of sending a package throughthe postal system.
   信封系数还用于计算通过邮政系统发送包裹的成本。
3. 3. Theenvelope factor can affect the cost of shippinginternationally, as it takes into accountfactors such as weight and size.
   信封系数会影响国际运输的成本，因为它考虑了重量和尺寸等因素。