Outlook 2007 Problems

[IBM]

I am using Outlook 2007 for email and unable to send emails getting the message below.  I have tried the repair tool and restarted numerous times but still not fixed.  With a help from google I found Stellar pst repair tool for outlook, free download 100% secure.  Should I try this?  Any advice appreciated.  

[Scotty]

not sure what you tried already or how big the PST file is but this page is recent :  https://docs.microsoft.com/en-us/outlook/troubleshoot/data-files/how-to-repair-personal-folder-file

Have not used stellar, but it gets good reviews. maybe try duplicating the file first and try it on the copy ?

I used to keep a ton of PST files for work but we transitioned to office365 and i did the same for personal use. Now i have 1TB space for Onedrive in my subscription and my outlook mailbox is 50GB on top of that. I think free outlook.com accounts even get about 15Gb. I can use word/excel/outlook online or install it locally and i can import gmail and my home email into it without hassle - highly recommend it if you do get your pst back.