Is it proper to use your cell phone to check voicemail while someone is speaking?

I was sitting with a fellow Muslim and we were having a conversation. In the middle of the conversation as I was speaking, he decided to pick up his cell phone and check his voicemail. Is it appropriate Islamically to interrupt someone while they are speaking with excusing oneself first in order to check voicemail? What is the proper adab with regards to conversation?

Walaikum assalam wa rahmatullah,

I pray that this finds you well, and in the best of health and spirits. May Allah grant you all good and success in this life and the next.

The sunna of the Messenger of Allah (peace and blessings be upon him) exemplifies excellence in all matters--whether worship, dealings, conduct, or character.

The sunna of social interaction is normally to give one's full attention to the person whom one is addressing. It is mentioned in the descriptions of the Messenger of Allah (peace and blessings be upon him) that when he would turn to someone, he would turn completely, [Sunan al-Tirmidhi, 3571] giving his full attention to them.

Thus, proper manners would entail to excuse oneself before checking voicemail or making a call when one is engaged in a conversation with someone. Even in urgent situations, this wouldn't take more than a moment.

At the same time, one should keep a few things in mind:

(1) While one demands excellence from oneself in one's dealings with others, one should be easygoing with others; consider their circumstances (e.g. maybe there was a genuinely urgent matter that was busying his mind); and make excuses for them.

(2) Between close friends, there is a certain amount of relaxation of social norms and less formality. But this should be with discretion and consideration of the other person's feelings.

And Allah alone gives success.

Faraz Rabbani

سنن الترمذي - (ج 12 / ص 90)
إِذَا مَشَى تَقَلَّعَ كَأَنَّمَا يَمْشِي فِي صَبَبٍ وَإِذَا الْتَفَتَ الْتَفَتَ مَعًا