When installing PHP from source, i get following error

configure: error: utf8_mime2text() has new signature, but U8T_CANONICAL is missing. This should not happen. Check config.log for additional information.

This is required to compile PHP with IMAP support. Fixed by installing libc-client. Now i got another error

configure: error: Cannot find imap library (libc-client.a). Please check your c-client installation.

This is fixed by installing

yum install -y libc-client.x86_64 libc-client-devel.x86_64 libc-client.i686 libc-client-devel.i686