Nissan Motor Thailand (NMT) is one of the companies that are engaged in daily operation with diverse customers especially the Parts Logistics Department. This department corresponds with customers by using email transaction. In this context, understanding different communication strategies and interpersonal devices when dealing with overseas customers can be very important to understand different kinds of attitudes and communication strategies that are negotiated in the emails.The result of the study shows that there are various communication strategies used by different customers. These are politeness, clarification, acknowledgement, relationship bonding, lead in and topic focus strategies. Various attitudes [affect, judgment and appreciation] are also identified through the use of various lexico-grammatical items and other linguistic instruments such as 'modality', 'adverbials', 'capitalization and abbreviation' and 'punctuations'. These items indicate positive and negative attitudes while modalities in most cases are used to soften or sharpen the transaction.With the impact of AEC, this research supports the current policy of the company to promote NMT mindset about 'cross-cultural function' in both internal and external organizations
