I have multiple email accounts. And I just avoid them because it's so horrible trying to delete emails in a list.
I click FROM, leave the ones I want to get rid of 'checked' and click DELETE.
Biue wheels spin and spin. Nothing happens. I go through the entire thing 4 or 5 times before emails vanish. And, often it isn't all 20 of them.
This is horribe. I can't deal with this slow movement.
I just tried it with the 'Ethernet", skipping the Wi Fi router, and it's no different.
I have 8,000 on one email address because it drives me nuts thinking of spending the time getting rid of them.
I have friends and relatives that changed from SPECTRUM because they couldn't bear this anymore.
I see commercials for SPECTRUM, and the fast internet. I'm paying way too much every month to get such crummy internet.
WHICH, by the way, is often off tine for hours during the day.
I'm paying way too much for way too little.
Before all these 'improvement' changes I never had any problems with the internet, speed or quality.
Cable providers, Dish, U-Verse, often provide email as a general courtesy service only with updates more so to TV, Internet, Mobile, and in some instances, such as Spectrum, landline phone. Although they still update email from time to time, most of us here have switched to a faster and free Web Mail provider.
Gmail, Yahoo Mail, and Outlook.com all provide free email for life across any computer or device with an Internet Connection. Just get one pop-up blocker for each web browser to stop the ads. (More than one will conflict.) I recommend Ad Block Plus.
With free webmail, you will be treated to a faster, more modern, and updated more often interface with better security than Spectrum Email. Additionally, Gmail and Outlook.com will give you access to free online Office Suites (Google Drive) with your Gmail account, and Office.com (Free Microsoft Office/On Drive) with a Microsoft Account. You will have better file sharing and modern capabilities with a webmail provider. If Spectrum dumps email, you will lose all of your messages and contacts, not so with webmail, which will provide you with a free account for the rest of your life from any browser and Internet device anywhere in the world.
This is not an internet issue but rather a Spectrum email issue.
Are you using webmail or some other client like Outlook?
I will second @Satch comments that it is generally in one's best interest to use a stand-alone email service that isn't tied to your ISP. You'll realize better performance and if you ever want to switch ISPs you won't lose your email address.