写一封告别信时，你可以遵循以下步骤和结构：

称呼

亲爱的 [收信人的名字或称谓]，

开场白

我写这封信是为了正式通知你，我将会离开 [你的组织或离开的原因]。

表达感受

在做出离开的决定之前，我经过了深思熟虑。我感到有些难过，因为我不想离开你们。

感谢与回忆

我想借此机会感谢你们在我在这里的这段时间里给予我的支持和友谊。

我永远不会忘记我们一起度过的美好时光和共同取得的成就。

告别

我将开始新的篇章，希望我们能够保持联系。

祝愿你们一切顺利，期待未来有机会再次相见。

结束语

真诚地，

[你的名字]

```

Dear [Recipient's Name],

I am writing to formally inform you that I will be leaving [your organization or reason for leaving]. After much thought and consideration, I have decided that it is time for me to move on to new opportunities.

I want to take this opportunity to express my deepest gratitude for the support and friendship you have shown me during my time here. Your guidance and encouragement have meant a great deal to me, and I will cherish the memories of our time together.

It is hard to believe that I will no longer be a part of your team, but I am excited about the new challenges and adventures that lie ahead. I am confident that [your organization or the future] will continue to thrive and achieve great things.

Thank you once again for everything. I look forward to staying in touch and wishing you all the best for the future.

Sincerely,

[Your Name]

```

请根据你的具体情况和感受，调整上述模板中的内容，使其更加个性化和真诚。