These are SMTP logs, generally used for troubleshooting purpose, you may delete them, (If you want to keep the files for any reason, zip the files and move to another drive), this doesn't create any issues.
Refer this article for more details.
http://www.msexchange.org/tutorials/Logging_the_SMTP_Service.html
The second folder is Catalog folder for Symantec Backup Exec, Catalogs are files which contain information about what files have been backed up. You may move the folder to another drive.
Refer the article for details.
http://www.backupexecfaq.com/articles/problems/catalog-folder-is-growing-too-large.html