What is the best type of inter-office communication?

Thanks 

I support my colleagues answers 

It depends on what you want to communicate. For some verbal instruction would be enough, for some, you need to have an official or unofficial meeting and some have to be on email to record the status.

It really is a question of what you want to communicate. Horses for courses, if the distance between offices are great, email, telecom and mobiles are fine. If the opportunity exists to face to face always more conveyed than remote. Formal communications like reports or responses to performance or compliance questions probably best as a document with a one page summary. 

Email is the most commonly used inter office communication. Dictate clear guidelines to your team and require that emails follow a specific protocol. 

Use intercom and do one to one discussion.   

I think the best form of communication still is face to face communication no matter how much technology we use for convinience. Telling you from experience, no matter how many tools, channels and communication strategy you have internal communication best happens in person. 

If you are talking about communication with customers then you need to have a strategy to use channels which is most effective. Eg, social media in current scenario. 

A mix of e-mail, Intranet and weekly or bi-weekly team meetings

sitting around the table with all parties

Inter office communication is a major function of the modern office and choosing the best strategies for maintaining open and seamless communication is vital.  Emails, Notes, Meetings, Intranet are most often used communication tools.  Interpersonal office coomunication should be immediate to increase the flow of information & to produce good outcome. Take advantage of instant messaging. Instant messaging can optimize your company's inter-office communication because it is answered in seconds rather than minutes. In some cases seconds can count.