Samsung Galaxy S2 - updated software issue?

[#1]

Been on the planet for almost 70 years and still not mastered technology! 
My android 'Samy' Galaxy S2 (on the O2 Network), received a download of a software update last week.  Since then my emails have gone haywire.  I cannot get an icon for my 'Plusnet'  Webmail.  I have three email addresses, ( one is a POP3 and two are webmails), which I used to be able to 'Combine' for display, via the 'Email' setting.  Now I only receive downloads from the one 'POP3' address!  I do however receive 'Gmails', but have to check separately via the Gmail icon.  I am not receiving any sent to my 'Plusnet' email address! 
To add one more irritation...after I have 'deleted' read mails manually....I get them re-offered a short time later, some going back a day....some going back months!!  Often I get the same deletions recurring.  It's almost like a 'server issue', but I doubt it is....cos its run by Yorkshiremen.
If any kind and knowledgeable soul can help me with some advice as to how to overcome these issues...I would be most grateful.  Thank you in advance for your considerations - you 'are' appreciated.
Regards and thanks from 'DickyP'.

[#2]

I've also got a Samsung S2 and it's on the O2 network. I'm currently on 4.1.2 version which was updated about 2 months ago.  What version are you on?

[#3]

Hello - thanks for getting back to me.  I am unsure what the version is called...some daft name about Ice-cream or Jelly Beans or something FGS!
I was notified of the available update and felt it would be sensible to accept it.  That's when my problems started! 
My previous email settings had worked well, but seem now to have been corrupted in some way.  Even reading threads and messages from others on the forum....their advised settings are not working when applied to my S2? Weird or what?

[#4]

Me again!  Just managed to locate the newly updated version: It's Android 4.1.2  Cheers de Richard.

[#5]

Yes, that's the latest version.
Whenever I've had a problem with my S2 I've always found O2 very helpful.  it's worth giving them a call.
Alternatively I've also had very good help from PN in the past.  Not really their problem but they may be worth a call.
Let us know how you get on.
BTW, welcome to the forums.

[#6]

One simple thing to check.  Have you got sync email ticked.  If not tick it and then see if you can receive your emails normally.

[#7]

Greet's 'artmo' and thank you for continuing your support and advice - you 'are' appreciated.
Yes..been to the 'O2' franchise shop locally this morning.  I embarrassed myself in front of 'the world', by realising I had not picked-up my 'Samy' before leaving the house!
As for contacting both 'O2' and 'Plusnet' by phone, good advice.  I may have to wait a day or two as travellig away for a few days in a few minutes.
Thanks for your welcome.  Nice making your acquaintance.  Greet's from 'sunny' (it says 'ere) Scarborough.
DickyP.

[#8]

Just a heads up, I think it's a software issue.
I have a Galaxy S4, on Three network.
I also get emails previously deleted popping up again, some dating back 2 months or more.
I have tried everything, and don't seem able to fix it!

[#9]

If it is a software issue then it might be worth you trying an alternative mail client. My Android email client of choice is K9.