Dear 称呼,

On behalf of 机构/组织名称, I would like to invite you to be 对方在活动中担任的角色 for 活动名称. 活动名称 is a 活动性质. 邀请对方的原因, so we would be greatly honored if you could be precent at 活动名称.

活动名称 will be held at 活动举办的时间/地点. 活动其他相关信息/注意事项.

We look forward to your presence and please let me know your decision. Thank you for your time and consideration.

结束语,

Li Ming

Dear Professor Smith

I’m very sincere to inviting you to ba a judge for the upcoming English speech contest.

First of all, this English speech contest is a rare chances for colledge students showing thier English learning outcome.

In addtion, you are my favorate English foreign teacher, we expecting yours presence and guidance.

Finally, after speech contest, every judge will recieve a mystery gift. I know you won’t miss it.

I hope to get your response.

Best wishes,

Yours Li Ming