PHP缺少输出/输出没有我期望使用echo“mail from:<anything>”; - 输出邮件来自:

I am having trouble with outputting the following:

$i = "MAIL FROM:<test@example.co.uk>";

Attempting to connect to 'alt3.gmail-smtp-in.l.google.com' on port '25'...
220 mx.google.com ESMTP r64-v6si10402557pfd.37 - gsmtp 
MAIL FROM:502 5.5.1 Unrecognized command. r64-v6si10402557pfd.37 - gsmtp

As you can see Gmail server only sees MAIL FROM: as PHP seens to strip the <\test@example.co.uk> hence the Unrecognised command. I can't use html entities as it is being sent over a network stream so the stream will show '&#62;' rather than > any Ideas how to send "<" and ">" would be appreciated.