The first thing you should probably try while working with simple ciphers is calculating the index of coincidence, for the given ciphertext it turns out to be 0.06618, pretty close to that of English plaintext at 0.0667. A low IC(around or lower than 0.04) indicates a flatter probability distribution(that is, random text), while a high IC(around or higher than 0.06) indicates either a transposition cipher or a monoalphabetic substitution cipher.
The next thing which you can try to be sure is checking letter frequency.
Comparing the above distribution, one could easily tell that no substitution is involved (hopefully), which means the given thing would be transposition cipher.
Thinking of various transposition ciphers, the first one which comes in mind railfence cipher.
Once again, I am asking for help from dcode.fr, and it does help (with removed punctuations and spaces option)
to give out plaintext
Key Railfence size 5, offset 3, from bottom
Putting correct spaces, we can read
Plain text
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AGENT GREAT WORK WITH THE FIRST MESSAGE I NEVER WOULD HAVE THOUGHT IT WOULD
BE A SIMPLE CAESAR CIPHER IT LOOKS LIKE EVIL CORP ARE DEFINITELY UP TO
SOMETHING SUSPICIOUS ROCCO AND DONNIE BOTH APPEAR TO BE SENIOR MEMBERS OF
THE COMPANY BOARD SO THIS COULD BE REALLY BIG WE MANAGED TO INTERCEPT
ANOTHER MESSAGE BETWEEN THE MBUT IT LOOKS LIKE THEY VE INCREASED THEIR
SECURITY A BIT MORE THE CRYPTOLOGISTS ARE STILL ON LEAVE AND NONE OF THEM
ARE RESPONDING TO THEIR EMAIL I ASSUME WE CAN CONTINUE TO COUNT ON YOU FOR
THESE WHEN WE FOUND THE MESSAGE IT CAME WITH A SLIP OF PAPER WHICH I VE
INCLUDED A PHOTO OF FOR YOU ALL THE BEST AGENT B THE SECRET CODE IS
ANUALLEAVE WITHOUT ANYSPACES
And ANUALLEAVE is finally the secret code which we seek
Check this video by @hyperreality for a better analysis