$re = '/(\d{2}\/\d{2}\/\d{4}),\s(\d(?:\d)?:\d{2})\s-\s([^:]*):\s(.*?)(?=\s*\d{2}\/|$)/m';
$str = ' 09/05/2016, 13:11 - Joe Bloggs: Hey Jane how\'re you doing? ? what dates are you in London again? I realise that June isn\'t actually that far away so might book my trains down sooner than later!
09/05/2016, 13:47 - Jane Doe: Hey! I\'m in london from the 12th-16th of june! Hope you can make it down :) sorry it\'s a bit annoying i couldn\'t make it there til a sunday!
09/05/2016, 14:03 - Joe Bloggs: Right I\'ll speak to my boss! I\'ve just requested 5 weeks off in November/December to visit Aus so I\'ll see if I can negotiate some other days!
When does your uni term end in November? I\'m thinking of visiting perth first then going to the east coast!
09/05/2016, 22:32 - Jane Doe: Oh that\'ll be awesome if you come to aus! Totally understand if it\'s too hard for you to request more days off in june.
I finish uni early November! So should definitely be done by then if you came here
09/05/2016, 23:20 - Joe Bloggs: I could maybe get a couple of days ? when do you fly into London on the Sunday?
Perfect! I need to speak to everyone else to make sure they\'re about. I can\'t wait to visit but it\'s so far away!
09/05/2016, 23:30 - Jane Doe: I fly in at like 7.30am so I\'ll have that whole day!
I\'m sure the year will fly since it\'s may already haha
09/05/2016, 23:34 - Joe Bloggs: Aw nice one! Even if I can get just Monday off I can get an early train on Sunday ?
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php