more options for email notifications

1. 现在的邮件通知方式是新帖子全员通知，会造成一瞬间发送大量email的情况，邮件服务商似乎没法全部成功处理，是否可以增加一个每封邮件之间的发送间隔的设置
2. 提问回复可以立即发送邮件通知，这个没问题。新帖子和关注标签，是否可以改成一天发送一次
3. 如果用户处于登录状态，站内提醒就可以。建议此时不发送email通知，以免用户email收到大量通知类邮件。
   谢谢

[mysterious-cod1004]

Can I resolve it now ?

[LinkinStars]

@mysterious-cod1004

1. I think this problem can be solved by adding an environment variable. And we can set a default value. You can try to resolve it.
2. If you feel the notifications are too frequent, you can proactively turn them off. But once a day seems easy to miss. So for now, no need to make any changes.
3. There are currently no in-site reminders/notice, so no need to make any changes for now.

[AsyncAssassin]

Hi, I’d like to work on the first item here.

Based on the comment from @LinkinStars, I’ll keep the scope limited to adding a configurable interval between emails sent for new-question / followed-tag notification fan-out. I won’t change daily digest behavior or logged-in user handling in this PR.

My current plan is to use an env var with a default that preserves the current behavior, and apply the delay only to these notification emails, not to verification, password reset, or SMTP test emails.

[LinkinStars]

Hi, I’d like to work on the first item here.

Based on the comment from @LinkinStars, I’ll keep the scope limited to adding a configurable interval between emails sent for new-question / followed-tag notification fan-out. I won’t change daily digest behavior or logged-in user handling in this PR.

My current plan is to use an env var with a default that preserves the current behavior, and apply the delay only to these notification emails, not to verification, password reset, or SMTP test emails.

@AsyncAssassin That's a good plan.