As the sponsor we will receive an electronic TMF compiled by the CRO during a phase-3 study. What are the requirements regarding IT to be able to archive the TMF 'forever'. Would a server that automatically and regularly creates copies of the content be sufficient? Can the documents be in MS-Word or Excel or do they need to be pdf files? Will scanned signature pages count as originals? In what format should e-mail correspondence be archived? Where could I find some guidelines/guidance documents on the subject?