In order to express your appreciation for a networking event that really helped your cause, either personally and professionally, you should write a thank you email.
Start the email with opening salutation. Since most of the times you know the person you are writing the email to, it is better to write their name in the salutation. Writing Dear (name) sounds more intimate and more professional. However, you can also write Dear Sir.
The first paragraph of the email should be about appreciation and gratitude for the recipient, who played his/her part in organizing a networking event that helped you. In the opening paragraph, you must state why you are writing this email, so the reader can understand how important the message is.
In the second paragraph, tell the reader how the networking event that he/she organized helped you and how important it was for both of you and other people. If there was something really good in particular at the networking event, do not forget to mention it.
In the last paragraph, express your thanks once again and state how you plan to interract in future.
Use salutation to conclude the email. Write “Sincerely,” if you have used the recipient’s name in the opening salutation.