Let this post be a little professional. Everyday we send and receive multiple E-Mails as a part of our day to day activity. You can witness people using abbreviations very frequently in Business E-Mails. Hope this little excerpt will help you.
1. ASAP - As Soon As Possible
2. AFAIK - As Far As I Know
3. b/c - Because
4. b/w - Between
5. B2B - Business To Business
6. Comp. - Commerce
7. Corp. - Corporation
8. Enc. - Enclosed
9. EOD - End Of Discussion/End Of Day
10. EOM - End Of Message/End Of Meeting
11. ETA - Estimated Time Of Arrival
12. FAQ - Frequently Asked Questions
13. FYI - For Your Information
14. FYI&A - For Your Information and Analysis
15. L/C - Letter Of Credit
16. NNTO - No Need To Open
17. NOO - Not On Original
18. OOO - Out Of Office
19. P.S - Post Script
20. PFA - Please Find Attached
21. pp - On behalf of
22. Ref - Reference
23. RSVP - Please reply
24. SPOC - Single Point Of Contact
25. TBA - To Be Announced
26. TBC - To Be Continued
27. TBD - To Be Determined
28. w/o - Without