如何通过逗号分隔显示名称和电子邮件地址检查电子邮件地址是否有效...
"a1 b.d"<a1@test.com>, // this is valid
<a2@test.com>, // this is valid
"a3 b.d"<a3@test.com> , // this is valid
a b.c a4@test.com , // this is not valid
"a1 b.d"<a1@test.com>, // this is valid
<a2test.com>, // this is not valid
"a3 b.d"<a3@testcom> , // this is not valid
" a b.c a4@test.com " , // this is not valid
整体是否有效?如何检查?