PHP如果电子邮件是回复或不回复[重复]

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I am using the PHP Function imap_open to get emails and insert them into a database.

Whats the best way to see if the email is a reply or not

i have tried:

if(!substr($subject,0,3) == 'RE:')

to see if the first 3 characters of the subject DO NOT equal RE: but that didnt work, i have also tried without the ! but that didnt work either

any ideas?

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You have a typo here.

if(!substr($subject,0,3) == 'RE:') should be if(!(substr($subject,0,3) == 'RE:'))

OR try !==

if(substr($subject,0,3) !== 'RE:')