问题
When sending an HTML e-mail, is there any sense in using the <title> tag? In the PHP Manual, for instance, they use such a tag in their main sample code. However, I see no reason why an e-mail client would use this title and not the Subject from the e-mail. Is there any reason to set this tag?
回答1:
I've been looking into this myself as I'm writing a PHP mailing list manager script that uses the sendmail() function.
The script allows the admin to create and send multiform emails (both text and html versions).
After much testing I have found that some email servers appear to have issues with the title tag (<title></title>).
I created a test email and sent it to 5 of my email address, my @blueyonder.co.uk email failed to arrive but the 4 others had no problems.
After a process of elimination it turned out that the @blueyonder.co.uk mail servers did not like the title tags in the html part of the email message, when I removed the tag the email arrived no probs.
Very strange!
回答2:
The only use I would see is that some clients, like Outlook, allow you to view an email in a browser for better rendering. It would then be a plus to have the html title tag set.
回答3:
(Old question, I know ;) )
My experience is that some mail clients will display the <title> tag in their email preview and some won't. Some clients preview will be "Subject + <title> + Preheader" and some will only be "Subject + preheader", so that creates an inconsistent experience.
Because of that, I found it's better to only use a preheader.
For completion's sake, the "Preheader" is a hidden text form the body that is only used in the preview, for example, something like...
<div style="display: none; max-height: 0px; overflow: hidden;">
Insert hidden preheader text here
</div>
来源：https://stackoverflow.com/questions/12237776/is-there-any-sense-in-using-the-title-tag-in-html-e-mail