I'd like to send this (by) recorded delivery.

这个邮件要挂号。

We recommend that you send your certificates by recorded delivery.

我们建议你用挂号邮寄你的证书。

Use recorded delivery for large cheques or money orders.

对于大额的支票和汇款单要使用挂号邮寄。

For applications made within the UK, all documents will be dispatched using Recorded Delivery.

对于在英国以内的申请，所有的文件将使用挂号邮递。

He has closed his personal office but mail continues to flood in, most of it by recorded delivery, so people know he has got it and will send it on to the right bureaucrat.

不过他仍然会收到大量的邮件，其中很多设置了收信回复，这样人们就能知道邮件是被杨建昌收到了，而且会被转发给相关负责人。