Read Franklin Graham’s facebook post:
Franklin Graham
12 hrs ·

President Obama will be meeting today with Pastor Saeed Abedini’s wife Naghmeh during his trip to Boise, Idaho. She has been waiting for her husband’s freedom from a cruel Iranian jail for nearly two and a half years. Please pray for this important meeting, for Saeed, and for persecuted Christians around the world.

You can write a letter to President Obama. Just address it to President Obama
The White House

Since the meeting is happening soon, an email would be better.
Simply visit his website, and leave a message right there on the contact form, encouraging hm to put pressure on the Iranian officials to free Pastor Saeed:
Contact him here:
Update: Pastor Saeed wrote a letter to President Obama thanking him for visiting with his wife.

The Promise Obama made to Pastor Saeed’s son

“Mr. President, can you please bring daddy home for my birthday?” The President responded, “When is your birthday?” Jacob told him March 17th, when he will turn 7. The President said he will try very hard to bring his father home.”