The long E [eː]
- does not exist in English
- is closed
The short E [ɛ]
- is available in English words like bed
- is a bit opener than the long E
E + R
E in front of an R is spoken a lot opener than the other two [æ]. It’s the same sound as in English cat.
The unemphasized E [ə] is called a Schwa and exists in for instance British English as the ending -er (cucumber) or in American English as the O in today.