EDIT : I agree one should check the reasons, why a senior level employee is leaving. But I am interested in knowing the official/management/technical/legal steps one should take after its decided that he is leaving, so that the life after him is smooth.

What are the steps management should take when a senior programmer/team lead leaves your company.

Some of them which I have thought about are :

1) If He used to manage hosting and domains stuff, change passwords of domain control panels and hosting panels.

2) If your published web sites have maintenance account and he is aware of credentials of that account then change this details also.

3) Suspend mail account for some time and forward all eMails of that account to some ex-employee account. After some time close that account.

What are the other things one should check. I am expecting the answer to be a general check list one should follow. It should include both technical scenarios and management scenarios.

Notable Suggestions so far :

• Effectively transfer the responsibilities of that employee to another one without causing any potential delay in your work.
• Protect your source code. If possible Make them to sign something to say that they don't have copies of source code.. You can also consider NDA here.
• Use the Notice Period to train his replacement. Now any new code to the project will be > done by replacement with the help of Guy who is leaving.
• Ask him to create a document of things he thinks you should know.
• Make sure he checks everything in now and then any checkout will only be done by the replacement.
• Emails, copy off his email account to a pst.file (this assumes Outlook), Make this file available to his replacement. the employee should probably be given a chance to scrub the email.
• if you are going to keep his account open for whatever reason, check that no rules are created that forward incoming emails to an alternate address.
• Copy the hard drive of his computer to a network location and have someone senior go through and see if there are any files (drafts of performance reviews or other sensitive issues ) on it that someone else might need.
• Clearance from Accounts,Finance,Security,Library etc departments.Obtain all company property, laptops, keys, etc.
• If there is no reason not to, you should reward a departing person for their many years of service. Write them letters of recommendation (even if they already have a new job lined up).Say goodbye, and keep the door open.
• Make sure any outside clients know that the departing employee is not their main contact anymore.
• Never neglect the exit interview/debriefing.
• Confirm the last day of employment so that there is no misunderstanding
• Inform H/R if the employee is on H1B status, there is paperwork required to notify the government when an H1B employee leaves.
• Depending on how senior / what position, you might spend some time convincing him not to take the rest of the engineering staff with him.
• Make sure he spends his last days on a good note, because if he is not leaving on a good note, he can easily pollute the mind of his colleagues.

Best Regards, Mahin Gupta

EDIT : Now offered a bounty on it to get more detailed responses and practical suggestions.